https://www.mathworks.com/matlabcentral/answers/questions MATLAB Answers — New Questions 2021-04-11T19:51:12Z tag:www.mathworks.com,2005:Question/771908 2021-03-13T18:47:56Z 2021-04-11T19:51:12Z Reinforcement Learning Onramp Issue I am working on this task and doing exactly what it says, even the solution has the same code for Task 3. I am not sure what I am missing. Could someone explain this pelase? Thank you! Nahid Hasan Tushar https://www.mathworks.com/matlabcentral/profile/authors/7344640 tag:www.mathworks.com,2005:Question/799147 2021-04-11T19:50:16Z 2021-04-11T19:50:16Z 3D Scatterplot and Pareto Front visualization Hey, So first things first, I'm really new in MatLab and even though I'm trying to learn the bassics in order to do what I want and udenrstand it, it seems like it is hard when you are under schedule. I've Uploaded an excel file with all my data ( 525 rows and 3 columns) and then I created my workspace. After that I defined my x's,y's and z's using the following commands. numbers = xlsread(filename); x = numbers(1:525,3); y = numbers(1:525,2); z = numbers(1:525,1); I tried following this answer ( https://www.mathworks.com/matlabcentral/answers/110723-is-it-possible-to-generate-surface-pareto-front-for-3-objective-functions-and-plot-it) but I had no luck - the first reason was because I couldn'y understand what a,b and c were and how they were related to my data. So my question is, how do I create a 3d scatterplot were I can also create a visible Pareto front? Thanks in advance! Apostolos Fragkalas https://www.mathworks.com/matlabcentral/profile/authors/22137277 tag:www.mathworks.com,2005:Question/431808 2018-11-25T12:45:01Z 2021-04-11T19:46:52Z drawing a function graph. Find the stationary points of the function and examine the quality of the function drawing a function graph. Find the stationary points of the function and examine the quality of the function: im sure i can draw the function but how do i find the stationary points? Gaston Gakomo https://www.mathworks.com/matlabcentral/profile/authors/12474209 tag:www.mathworks.com,2005:Question/799142 2021-04-11T19:43:19Z 2021-04-11T19:43:19Z How can I model a sequencing batch reactor in Matlab? Hi, I have to model a sequencing batch reactor in Matlab, particularly the feed and the react phases. As the feed phse is long enough, I have to model it taking into account both dilution with the influent and reactions which occur in the reactor. So, dilution is not istantaneous, and it must be occur together with dilution. I tried to model them one before each other, or also together (the latter calculating the average concentartion between diluted concentration and simulated concentration after reactions, with initial concentrations as initial condition). However, the overall concentration trend I obtained along the entire feed phase is not the same as what I got using other simulation software, which I know they are correct. Thank you for your answers! Elia Paini https://www.mathworks.com/matlabcentral/profile/authors/7115132 tag:www.mathworks.com,2005:Question/798827 2021-04-11T13:24:14Z 2021-04-11T19:42:51Z Goertzel Algorithm for calculating amplitude and angle Hello everybody! I have written a script that describes Goertzel Algorithm. The script is given below. The algorithm calculates correct real part but incorrect imaginary part of original signal. So how to receive the correct imaginary part? Sampling frequency (N) & nominal frequency (f) with simulation interval (t) are given as: N = 80; % points/period f = 50; % Hz t = 0.02; % s Time array is: TimeArray = 0:1/f/N:t; Original signal array is equal: x = cos(2*pi*f*TimeArray); The first part of Goertzel Algorithm is given below. % W - z^-1 % H(z) = --------------------------- % 1 - alpha * z^-1 + z^-2 % % W = W_N^(-k) = exp(2i*pi*k/N). % alpha = 2*cos(2*pi*k/N). k = 50; % Spectral sample number om = 2*pi*k/N; w = exp(-1i*om); %alpha alpha = 2*cos(om); s1 = 0; s2 = 0; for h7 = 1:length(x) s0 = alpha * s1 - s2 + x (h7); s2 = s1; s1 = s0; end The second part of Goertzel Algorithm is Xk. Xk is the algorithm output. Here Xk gives out complex number. However Xk gives me correct real and incorrect imaginary of complex number. Xk = s1 - w * s2; Ismoil Odinaev https://www.mathworks.com/matlabcentral/profile/authors/18248867 tag:www.mathworks.com,2005:Question/798387 2021-04-10T19:31:54Z 2021-04-11T19:38:02Z App designer - problem with thresholding image Hi folks, I have the app attached, in which I am encountering two issues. Firstly, when trying to threshold an image and displaying the thresholded image, it would appear my function calls aren't working as the image displayed is not thresholded. (ResinThreshold function works in live editor, but not when called in app designer). The thresholding function is below. Thanks function ResinThreshold(app) imgGrey = rgb2gray(app.img); [counts, ~] = imhist(imgGrey, 255); T = otsuthresh(counts); BW = imbinarize(imgGrey, T); BW = bwareaopen(BW, 3000); BW = imfill(BW, 'holes'); BW = bwperim(BW); BW = imdilate(BW, ones(5)); BW = imerode(BW, ones(3)); BW = imfill(BW, 'holes'); app.img = app.img.*repmat(uint8(BW),[1 1 3]); end Teshan Rezel https://www.mathworks.com/matlabcentral/profile/authors/17128181 tag:www.mathworks.com,2005:Question/799122 2021-04-11T19:07:09Z 2021-04-11T19:36:16Z My plot comes up as a white graph with no line. My homework is like that, This is about dynamic voltage stability, I can't code this equation. After that I eliminate T, because it is constant, then just calculate PR. I want to draw t,PR and t,VR graph. But i can't. Please help me. This question says Vr changes 1-0.9-1-1.05-1 respectively. then calculate Pr for T=1 and T<1,T>1. Thank you from now. When I try to plot with this code which is given below, nothing comes up. There are no errors, there's just nothing. I know, I only asking to draw one point at a time, so the plot has no information about which points should be connected. But i am new at Matlab, i can't able to draw graphic, please help me. Expected graphic is like that, clear all; clc; G=3; t1=1:5 VR1=1; PR1=G*VR1^2; t2=5:15 VR2=0.9; PR2=G*VR2^2; t3=15:25; VR3=1; PR3=G*VR3^2; t4=25:35; VR4=1.05; PR4=G*VR4^2; t5=35:40; VR5=1; PR5=G*VR5^2; hold on, plot(t1,VR1) plot(t2,VR2) plot(t3,VR3) plot(t4,VR4) plot(t5,VR5) xlabel('t(1/100)'); ylabel('VR'); title('PR Değişimi'); grid on Yunus Mercan https://www.mathworks.com/matlabcentral/profile/authors/19983468 tag:www.mathworks.com,2005:Question/787869 2021-03-30T11:35:16Z 2021-04-11T19:29:33Z How do i remove or disable or hide zoom in zoom out, save, brush tool from Matlab figures ? How do i remove zoom in zomm out, save brush tool from matlab figures, because it appear in publishing flies and cannot be removed. GAURAV BAKHRU https://www.mathworks.com/matlabcentral/profile/authors/20602548 tag:www.mathworks.com,2005:Question/799117 2021-04-11T18:48:58Z 2021-04-11T19:22:44Z Conversion From Gray scale to RGB colormap Hello, I am trying to convert images from gray scale to RGB. Firstly, I tried it for the jet colormap, but I would like to do this for other possible colormaps which MATLAB has. I imported the 'car1.jpg' image and converted via these lines: indexedImage = imread('car1.jpg'); Gray_Image= indexedImage(:,:,1)*0.299+indexedImage(:,:,2)*0.587+indexedImage(:,:,3)*0.114; Then I gave "Gray_Image" variable to my function "gray_to_jet" to convert RGB. Although output seemed like "jet", there are differences between MATLAB's jet colormap. How can I exactly map the values like MATLAB? I am new to image processing, so any help including theoritical appreciated. Here is my function: function [converted_image,Elapsed_time] = gray_to_jet(varargin) input_image = varargin{1}; [row_number, column_number] = size(input_image); C = uint8(255*colormap('jet')); % Convert 0-1 numbers in colormap to 0-255 and uint8. converted_image = zeros(row_number, column_number, 3); for idx = 1:row_number for jdx =1:column_number colormap_row= double(input_image(idx, jdx) ) + 1; new_red_pixel = C(colormap_row, 1); new_green_pixel = C(colormap_row, 2); new_blue_pixel = C(colormap_row, 3); converted_image(idx, jdx, 1) = new_red_pixel; converted_image(idx, jdx, 2) = new_green_pixel; converted_image(idx, jdx, 3) = new_blue_pixel; end end end Berkay Yaldiz https://www.mathworks.com/matlabcentral/profile/authors/10491148 tag:www.mathworks.com,2005:Question/798812 2021-04-11T12:48:36Z 2021-04-11T19:17:42Z How to stop blue highlighting of UITables created in app designer on cell selection How do I prevent uitables from hightlighting the cells when I click on them? I do not want to disable uitables because that would grey out the uitable. Kelvin L https://www.mathworks.com/matlabcentral/profile/authors/17026776 tag:www.mathworks.com,2005:Question/799132 2021-04-11T19:17:17Z 2021-04-11T19:17:17Z problems with rapid accelerator model When I try to compile Rapid accelerator model, I get this: Unable to build a standalone executable to simulate the model 'exp1' in rapid accelerator mode. Caused by: xcode-select: error: tool 'xcodebuild' requires Xcode, but active developer directory '/Library/Developer/CommandLineTools' is a command line tools instance Please download a supported version of Xcode at /Applications/MATLAB_R2019b.app/rtw/c/tools/macsdkver.pl line 24. xcrun clang -arch x86_64 -isysroot /Library/Developer/CommandLineTools/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk -mmacosx-version-min=10.9 -c -fno-common -fexceptions -DTGTCONN -DON_TARGET_WAIT_FOR_START=0 -DRSIM_PARAMETER_LOADING -O0 -DEXT_MODE -DIS_RAPID_ACCEL -DMODEL=exp1 -DHAVESTDIO -DUNIX -DNRT -DRSIM_WITH_SL_SOLVER -DENABLE_SLEXEC_SSBRIDGE=1 -DMODEL_HAS_DYNAMICALLY_LOADED_SFCNS=0 -I. -I../../.. -I/Users/derpy/work/Matlab/Group2 -I/Users/derpy/work/Matlab/Group2/slprj/raccel/exp1 -I/Applications/MATLAB_R2019b.app/extern/include -I/Applications/MATLAB_R2019b.app/simulink/include -I/Applications/MATLAB_R2019b.app/rtw/c/src -I/Applications/MATLAB_R2019b.app/rtw/c/src/rapid -I/Applications/MATLAB_R2019b.app/rtw/c/raccel -I/Applications/MATLAB_R2019b.app/rtw/c/src/ext_mode/common -I/Applications/MATLAB_R2019b.app/toolbox/coder/rtiostream/src -I/Applications/MATLAB_R2019b.app/toolbox/coder/rtiostream/src/rtiostreamtcpip -I/Applications/MATLAB_R2019b.app/toolbox/coder/rtiostream/src/utils /Applications/MATLAB_R2019b.app/rtw/c/src/rt_logging.c clang: warning: no such sysroot directory: '/Library/Developer/CommandLineTools/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk' [-Wmissing-sysroot] /Applications/MATLAB_R2019b.app/rtw/c/src/rt_logging.c:21:10: fatal error: 'stdlib.h' file not found #include <stdlib.h> ^~~~~~~~~~ 1 error generated. gmake: *** [rt_logging.o] Error 1 Why does it happen? One week ago it compiles properly. Matlab 2019b, MacOS 10.14.6, Xcode 11.3 (11C29) Semion Kurochkin https://www.mathworks.com/matlabcentral/profile/authors/9824285 tag:www.mathworks.com,2005:Question/798977 2021-04-11T16:26:43Z 2021-04-11T19:14:45Z Brace indexing is not supported for variables of this type. How do I call the sort_nat function to sort folders? clear all clc PF = 'D:\Project\DB1\test\' % Parent Folder SFL = dir(PF) ;% List the sub folders [mp1, np] = size(SFL); % compute size = number of subfolders & files & . & .. csf1=0; % counter of JUST subfolders found in PF t=1; for i=3:mp1 %% keep only folders: P = strfind(SFL(i).name,'.'); if isempty(strfind(SFL(i).name,'.')) csf1 = csf1 +1; % one sub folder found SFN = SFL(i).name ;% extract his name %----- [SFN,index]= sort_nat(SFN); c1 = [SFN,index]; %--------------- tifList = ls(sprintf('%s%s%s%s',PF,c1,'\','*.tif')); % list all jpg files [ms1, ns] = size(tifList); % ms = number of image files found %% Processing for each tif file: for j=1:ms1 tifFileName = tifList(j,:); % extract name of tif file Group_Test1(t)=[i-2] t=t+1; % PF_SFN_imgName = sprintf('%s%s%s',PF,SFN,'\',tifFileName); end end end save('Group_Test','Group_Test1'); sun rise https://www.mathworks.com/matlabcentral/profile/authors/16482360 tag:www.mathworks.com,2005:Question/798927 2021-04-11T15:18:25Z 2021-04-11T19:14:24Z Binomial Distribution when mean and variance is given How do i plot a Binomial Distribution when i have been given its mean and variance for example like mean = 3, variance = 3 or 0.5,2.......these values dont satisfy the conditions for mean and variance which are mean should lie between 0 and 1 and variance should be less than mean(mean - 1)...But these are the values i have to find the binomial distribution for...this is code i have written.... mu = 3; var = 3; alpha = (((1-mu)/var)-1/mu).*mu^2; beta = alpha((1/mu) - 1); X = 0:0.01:1; Y = betapdf(X,alpha,beta); %plot(X,Y,'LineWidth',1); xlabel('Thetha'); hold on mu2 = 0.5; var2 =2 ; alpha2 = (((1-mu2)/var2)-1/mu2).*mu2^2; beta2 = alpha2((1/mu2) - 1); X2 = 0:0.01:1; Y2 = betapdf(X2,alpha2,beta2); plot(X2,Y2,'LineWidth',1); hold off; Soham Baste https://www.mathworks.com/matlabcentral/profile/authors/19215162 tag:www.mathworks.com,2005:Question/799127 2021-04-11T19:12:09Z 2021-04-11T19:12:09Z How to define nested function? I want to define this f fucntion f = @(x,y)((2.*x+y).*(x<d & y<d)+ (3.*x.*y-1).*(x>d & y<d)+... (1+x+y).*(x<d & y>d)+ (3.*x+2.*y).*(x>d & y>d)+ ((2.*x(N/2)+y)+... (3.*x(N/2+2).*y-1)/2).*(x==d & y<d) + (((2.*x+y(N/2))+... (1+x+y(N/2+2)))/2).*(y==d & x<d)+(((1+x(N/2)+y)+... (3.*x(N/2+2)+2.*y))/2).*(x==d & y>d)+(((3.*x.*y(N/2)-1)+... (3.*x+2.*y(N/2+2)))/2).*(y==d & x>d)+(((2.*x(N/2)+y(N/2))+... (3.*x(N/2+2).*y(N/2)-1)+(1+x(N/2)+y(N/2+2))+(3.*x(N/2+2)+... 2.*y(N/2+2)))/4).*(x==d &y==d)); If i define like this, I am getting error which is mentioned below Error using trying1>@(x,y)((2.*x+y).*(x<d&y<d)+(3.*x.*y-1).*(x>d&y<d)+(1+x+y).*(x<d&y>d)+(3.*x+2.*y).*(x>d&y>d)+((2.*x(N/2)+y)+(3.*x(N/2+2).*y-1)/2).*(x==d&y<d)+(((2.*x+y(N/2))+(1+x+y(N/2+2)))/2).*(y==d&x<d)+(((1+x(N/2)+y)+(3.*x(N/2+2)+2.*y))/2).*(x==d&y>d)+(((3.*x.*y(N/2)-1)+(3.*x+2.*y(N/2+2)))/2).*(y==d&x>d)+(((2.*x(N/2)+y(N/2))+(3.*x(N/2+2).*y(N/2)-1)+(1+x(N/2)+y(N/2+2))+(3.*x(N/2+2)+2.*y(N/2+2)))/4).*(x==d&y==d)) Too many input arguments. Please help me to correct it. Thanks in advance. Aarthika Balakumar https://www.mathworks.com/matlabcentral/profile/authors/22006786 tag:www.mathworks.com,2005:Question/799102 2021-04-11T18:21:55Z 2021-04-11T19:07:55Z Image Segmentation - Watershed Algorithm I have followed the very helpful instructions on Steve Eddin's blog post concerning image segmentation of cells using the watershed algorithm. I have one piece to fine tune in my own image that I am working on. There are small sections in the cluster of cells in the top right corner where the algorithm produces segments for what should be the background. Can anyone suggest any strategies for resolving this? I am providing my code, the input image and my annotated output image showing the sections I would like to relegate to the background region. Input image (b&w), output image (rgb); arrows point to sections I am trying to address.: function A = getArea(I) level = graythresh(I); bw = imbinarize(I,level); %did not use imfill because this fills in area separating cells %bw = imfill(bw,'holes'); bw3 = imopen(bw,ones(5,5)); bw4 = bwareaopen(bw3,40); mask_em = imextendedmax(I,30); I_c = imcomplement(I); I_mod = imimposemin(I_c, ~bw4 | mask_em); L = watershed(I_mod); imshow(label2rgb(L)); end Rebecca Schley https://www.mathworks.com/matlabcentral/profile/authors/21410978 tag:www.mathworks.com,2005:Question/798882 2021-04-11T14:34:41Z 2021-04-11T19:04:47Z display of the intensity curve of the points hello everyone, I use this code to select points : IM=imread('capture.jpg'); imshow(IM); impixelinfo; [xi,yi]=getpts I want after the selection of the points, display a curve which contains the intensity of each point Amal Felhi https://www.mathworks.com/matlabcentral/profile/authors/22103929 tag:www.mathworks.com,2005:Question/798382 2021-04-10T19:26:34Z 2021-04-11T18:59:15Z App designer - deleting an unnamed plot Hi folks, I have the following code for generating 1 or multiple plots on an image. function ROI(app, index1, index2) hold (app.Image, "on") plot(app.Image, index1, index2, app.innerMarkerStyle, 'LineWidth', app.CrosshairThickness.Value, 'Color', app.crossHairColour, 'MarkerSize', app.CrosshairRadius.Value); plot(app.Image, index1, index2, app.outerMarkerStyle, 'LineWidth', app.CrosshairThickness.Value, 'Color', app.crossHairColour, 'MarkerSize', app.CrosshairRadius.Value); end My question is, suppose there are 3 such plots. Is there a way to delete 1 and only 1 of them selectively? Thanks Teshan Rezel https://www.mathworks.com/matlabcentral/profile/authors/17128181 tag:www.mathworks.com,2005:Question/799067 2021-04-11T17:53:25Z 2021-04-11T18:57:54Z Error using corrplot function Hi, I try to plot the correlation between two variables, but I keep getting a error: Undefined function 'corrplot' for input arguments of type 'double'. The code I used was: corrplot(KNMIGlobalestraling2018,DataHourlyTable.DataTableCorrect2) How can I fix this? Quincy Brouwer https://www.mathworks.com/matlabcentral/profile/authors/21481692 tag:www.mathworks.com,2005:Question/798992 2021-04-11T16:46:38Z 2021-04-11T18:50:20Z how can i sort excel file data of 2nd column of 1 row after that 430 row ,860 row,1290 row and so on mean column is fix but row increased by 430, all the values are numerical? how can i sort excel file data of 2nd column of 1 row after that 430 row ,860 row,1290 row and so on mean column is fix but row increased by 430, all the values are numerical? shivali atre https://www.mathworks.com/matlabcentral/profile/authors/2631660 tag:www.mathworks.com,2005:Question/799087 2021-04-11T18:14:13Z 2021-04-11T18:48:02Z Logistic Growth Model - Code and Plot I need to plot a differential equation that shows logistic growth. The equation is: P=(K*A*e^r*t)/(1+A*e^r*t) where K is the carrying capacity, a constant, and K = 1,704,885 and A = 0.0122. I need the correct code so that I can solve for r, as well as put different t to find the population at varying times. I also need to plot the solution. Thank you for any help! Emma Hadley https://www.mathworks.com/matlabcentral/profile/authors/21243913 tag:www.mathworks.com,2005:Question/799057 2021-04-11T17:43:13Z 2021-04-11T18:45:18Z How to find the nearby sampling stations I have millions of samping sations, my goal is to find the nearby stations with a certain distance threshold. What is the best way to do it based on the longitude and latitude information? It seems that calculating the stations between each of them is extremely time-consuming. Thanks. Leon https://www.mathworks.com/matlabcentral/profile/authors/3133287 tag:www.mathworks.com,2005:Question/799007 2021-04-11T16:51:06Z 2021-04-11T18:44:11Z gaussian regarding random variables what would be the pictorial difference of PDFs of X1 and Y = X1- X2 where X1 and X2 are gaussian random variables. I am getting error in the code. can someone please help me . Kinjal Agarwal https://www.mathworks.com/matlabcentral/profile/authors/19215341 tag:www.mathworks.com,2005:Question/799112 2021-04-11T18:24:09Z 2021-04-11T18:42:43Z Please change this code from inline to function. clear all clc format short f1=inline('2*x.^3+y.^3+x.*y-6'); f2=inline('x.^3-y.^3+x.*y-4;'); clear i X0=[i 1+i]; X1=[-i i-2]; X2=[i+1 1]; for k=1:21 M=[X0 1; X1 1; X2 1]; v=[f1(X0(1),X0(2)); f1(X1(1),X1(2)); f1(X2(1),X2(2))]; c1=M\v; v=[f2(X0(1),X0(2)); f2(X1(1),X1(2)); f2(X2(1),X2(2))]; c2=M\v; c=[c1';c2']; X=-c(1:2,1:2)\c(:,3); X0=X1; X1=X2; X2=X'; end 지원 안 https://www.mathworks.com/matlabcentral/profile/authors/21640167 tag:www.mathworks.com,2005:Question/799017 2021-04-11T17:02:53Z 2021-04-11T18:39:42Z volumeofsphere matlab function need help I put 10^4 into the function and I should be expecting Number of points inside sphere to be 3 and the area should be 0.0024. Am I missing something if so what do I need to change ? function volumeofsphere3(n) ds = RandStream.getGlobalStream; reset(ds); x=2*rand(n,1); y=rand(n,1); z=rand(n,1); count=0 for i=1:n r=sqrt((x(i)-1/3)^2+(y(i)-1/3)^2+(z(i)-1/2)^2); if r<=0.04 count=count+1; end end fprintf(1,'Number of points inside sphere: %d\n', count) Area_of_Sphere=8*(count/n) end gracias claude https://www.mathworks.com/matlabcentral/profile/authors/21366237 tag:www.mathworks.com,2005:Question/798807 2021-04-11T12:36:25Z 2021-04-11T18:36:47Z Trouble solving ODE equations I am trying to solve these differential equations in order to plot graphs, however, when running the code I am receiving multiple errors but I'm unsure why as I can't see why the code is not running smoothly? I'm looking for some insight on why this might be happening and how I can solve the problem? Equations and Parameter values: function dydt = Dunster(t,y) %Parameters and their values% K1a = 20; Y1a = 1; K1b = 0.25; K2a = 14; K2am = 72; K2b = 2.6; K2bm = 10; K2c = 24; K2cm = 20; K3a = 10; K3b = 0.05; K3c = 24; K3cm = 20; K4a = 2.3; K4am = 58; K4b = 2000; K4bm = 210; K4c = 1.3; K5a = 0.0014; K5b = 0.35; K6 = 2000; K6m = 2000; Kx = 50; Kb = 0.01; Lb = 1; Lx = 1; Bxva = 0; H = K1a*Y1a*exp(-Y1a*t); bl = 0.5*((Kb+Lb+Bxva)-sqrt((Kb+Lb+Bxva)^2 - 4*Lb*Bxva)); %Equation 1% %Generation and inactivation of factor Xa% F1= y(1); %y(1)= -K6*F1; % Factor I %Equation 2% F5=y(2); %y(2)=(-K2a*F2a*F5)/(F5+K2am(1+F1/K6m) - ((K2b*F10a*F5)/F5+K2bm(1+F2/K4am))); %Equation 3% F2=y(3); %y(3)= ((-K4a*F1*F2)/F2+K4am(1+F5/K2bm))-((K4b*b1*F2)/(F2+K4bm)); %Equation 4% C=y(4); %y(4)= (-K5a*C); %Equation 5% F10a=y(5); %y(5)= H +(K3c*Ca*Bxva)/(Bxva+K3cm) - K1b*F10a - K3a*F10a*F5a; %Equation 6% F5a=y(6); %y(6)= (K2a*F2a*F5)/(F5+K2am(1+F1/K6m)) + (K2b*F10a*F5a)/(F5+K2bm(1+F1/K4am))+ K3b*Bxva - (K2c*Ca*F5a)/(F5a+K2am) - K3a*F10a*F5a; %Equation 7% Bxva=y(7); %y(7)= K3a*F10a*F5a - K3b*Bxva - (K3c*Ca*Bxva)/(Bxva+K3cm); %Equation 8% F2a=y(8); %y(8)= (K4a*F1*F2)/(F2+K4am(1+F5/K2bm)) + (K4b*BF2)/(F2+K4bm) - K4c*F2a; %Equation 9% Ca=y(9); %y(9)= K5a*C - K5b*Ca; %Equation 10% F10i=y(10); %y(10)= K1b*F10a + K3b*Bxva; %Equation 11% F5i=y(11); %y(11) = (K2c*Ca*F5a)/(F5a+K2cm) + (K3c*Ca*Bxva/(Bxva+K3cm)); %Equation 12% F2i=y(12); %y(12) = K4c*F2a; %Equation 13% Ci=y(13); %y(13) = K5b*Ca; %Equation 14% F1a=y(14); %y(14) = K6*F1; dydt=[ -K6*F1; % d F1 / dt ((-K2a*F2a*F5)/(F5+K2am*(1+F1/K6m)) - ((K2b*F10a*F5)/F5+K2bm*(1+F2/K4am))); % d F5 / dt ((-K4a*F1*F2)/(F2+K4am*(1+F5/K2bm))-((K4b*bl*F2)/(F2+K4bm))); % d F2 / dt -K5a*C; % d C / dt H+(K3c*Ca*Bxva)/(Bxva+K3cm) - K1b*F10a - K3a*F10a*F5a ; % d F10a / dt (K2a*F2a*F5)/(F5+K2am(1+F1/K6m)) + (K2b*F10a*F5a)/(F5+K2bm(1+F1/K4am)) + K3b*Bxva - (K2c*Ca*F5a)/(F5a+K2am) - K3a*F10a*F5a; % d F5a / dt K3a*F10a*F5a - K3b*Bxva - (K3c*Ca*Bxva)/(Bxva+K3cm); % d Bxva / dt (K4a*F1*F2)/(F2+K4am(1+F5/K2bm)) + (K4b*BF2)/(F2+K4bm) - K4c*F2a ; % d F2a / dt K5a*C - K5b*Ca ; % d Ca / dt K1b*F10a + K3b*Bxva ; % d F10i / dt ((K2c*Ca*F5a)/(F5a+K2cm) + (K3c*Ca*Bxva/(Bxva+K3cm))) ; % d F5i / dt K4c*F2a ; % d F2i / dt K5b*Ca ; % d Ci / dt K6*F1 ; % d F1a / dt ]; end Running Part of the Code: tspan=[0 60]; F1=10000; F5=30; F2=1000; C=100; F10a=0; F5a=0; Bxva=0; F2a=0; Ca=0; F10i=0; F5i=0; F2i=0; Ci=0; F1a=0; y0=[F1;F5;F2;C;F10a;F5a;Bxva;F2a;Ca;F10i;F5i;F2i;Ci;F1a]; [t,y]=ode45(@Dunster, tspan, y0);%,[], pars); plot(t/60, y(:,14)*1000, "r") xlabel("Time [Min]") ylabel("Concentration [nM]") Jack Mulrooney https://www.mathworks.com/matlabcentral/profile/authors/20657737 tag:www.mathworks.com,2005:Question/746437 2021-02-16T02:48:58Z 2021-04-11T18:35:00Z How to correctly use MONTHS function? I am trying to find the difference between dates in "months". I have refferred to the following documentation on usage of "months" function and I even tried out the example given in the documentation but all I get is an error. https://in.mathworks.com/help/finance/months.html Code: MyMonths = months('may 31 2000', 'jun 30 2000', 1) Error: Check for missing argument or incorrect argument data type in call to function 'months'. What am I missing? Namrata Goswami https://www.mathworks.com/matlabcentral/profile/authors/20826718 tag:www.mathworks.com,2005:Question/798592 2021-04-11T04:39:29Z 2021-04-11T18:34:58Z Symbolic printing without extensive decimals syms x f=x*1231871.1561876*5618965/3156651894-561894+4849159*15844/5189; l=vpa(x*1231871.1561876*5618965/3156651894-561894+4849159*15844/5189); fprintf('%s\n',f) fprintf('%s\n',l) (1351321833700369665875*x)/616259847708475392 + 7647426328677875/536870912 2192.7792938728320167173931401797*x + 14244441.555212950333952903747559 I am trying to get my problem to print more efficiently, I have tried the vpa tool, and it works nicely, but I have no customization (as far as im aware) as to how to control the number of decimal places on the polynomial that is being printed using these commands while having a symbolic function/polynomial. How can I tidy up this so that it prints in an easier to read format, with, for example, 5 decimal places rather than the amount it has? Ramses Young https://www.mathworks.com/matlabcentral/profile/authors/22161720 tag:www.mathworks.com,2005:Question/799107 2021-04-11T18:22:19Z 2021-04-11T18:22:19Z Bus elements with multiple dimensions I have a structure S with three time series fields a, b and a. S.a = timeseries S.b = timeseries S.c = timeseries I'd like to create a bus object (B) with above bus element. But instead of creating 3 bus elements (a, b and c) I'd like to create one bus element (S) with dimention of 3. I created the bus B like this: S = Simulink.BusElement; S.Name = 'S'; S.Dimensions = 3; B = Simulink.Bus; B.Elements = S; How can I assing (sub)bus elements (a, b and c) to S (and B)? Alborz Sakhaei https://www.mathworks.com/matlabcentral/profile/authors/21653044 tag:www.mathworks.com,2005:Question/799097 2021-04-11T18:15:37Z 2021-04-11T18:21:51Z Index a Matrix that gets smaller I have a cell array that I am deleting any rows with empty values, and while indexing I run into the error: "Index in position 1 exceeds array bounds (must not exceed 347)." Here is the script for the part that has the issue, how can I index a cell array while deleting stuff as it goes? for ind=2:size(RAW) if sum(strcmp('',RAW(ind,4:7)))~=0 RAW(ind,:)=[] end end note: I am skipping the first row intentionally, and also only checking columns 4 through 7 Bryson Prince https://www.mathworks.com/matlabcentral/profile/authors/21088507 tag:www.mathworks.com,2005:Question/799047 2021-04-11T17:37:24Z 2021-04-11T18:20:23Z hs923a function for Monte Carlo Approx I found this function online and getting an error when using halton. Has the function changed in Matlab if so what do I use now ? function hs923a(n) x=2*halton(2,n)-1; y=2*halton(3,n)-1; count=1; for i=1:n if x(i)>=-1 if y(i)<=1 if 13*(x(i)^2)+34*x(i)*y(i)+25*y(i)^2 <= 1 count=count+1; end end end end disp(['Number of points inside the ellipse =', num2str(4*count)]) end gracias claude https://www.mathworks.com/matlabcentral/profile/authors/21366237 tag:www.mathworks.com,2005:Question/799092 2021-04-11T18:15:00Z 2021-04-11T18:15:00Z Can I track how often and who have viewed the shared channel of mine for a day or a month if I shared my private channels with others on ThingSpeak or ThingView? Thanks in advance. Jaewoo Lee https://www.mathworks.com/matlabcentral/profile/authors/22166734 tag:www.mathworks.com,2005:Question/799042 2021-04-11T17:36:35Z 2021-04-11T18:12:59Z How to convert arc length to km? My goal is to find a good function to calculate the distance for two points for millions of data points. I found the fucntion lldistkm in the FileExchange. Unfortunately, that function does not seem to work well for column data. It only works well for single data points. Lon1 = -78.1982; Lat1 = 33.8282; Lon2 = -77.5003; Lat2 = 32.8499; Distance_km = lldistkm([Lat1, Lon1],[Lat2, Lon2]) Distance_arc = distance(Lat1, Lon1, Lat2, Lon2) Here is my question. If I will rely on the Matlab function distance (see above) in the mapping toolbox to calcualte the distance. It's results will be in arc length? How do I convert it from arc length to km? Their ratio should be around 111 depending on the latitude. So rad2km is the wrong function? It does not give me a number close to 111 at all. Many thanks. Leon https://www.mathworks.com/matlabcentral/profile/authors/3133287 tag:www.mathworks.com,2005:Question/799037 2021-04-11T17:32:12Z 2021-04-11T18:11:19Z 2 digits after the dot Hi In the following example where do I put: ,'%0.2f' x = [1 2 3]; vals = [2 3.3333333 6; 11 23 26]; b = bar(x,vals); xtips1 = b(1).XEndPoints; ytips1 = b(1).YEndPoints; labels1 = string(b(1).YData); text(xtips1,ytips1,labels1,'HorizontalAlignment','center','VerticalAlignment','bottom') xtips2 = b(2).XEndPoints; ytips2 = b(2).YEndPoints; labels2 = string(b(2).YData); text(xtips2,ytips2,labels2,'HorizontalAlignment','center','VerticalAlignment','bottom') Same problem here: x = 0:pi/100:2*pi; y = sin(x); plot(x,y) my_num= 3.33333 text_information =['my num is : ' num2str((my_num))]; xlabel(text_information); xlabel(text_information,'interpreter','latex') tnx :) Shahar ben ezra https://www.mathworks.com/matlabcentral/profile/authors/17813425 tag:www.mathworks.com,2005:Question/799072 2021-04-11T17:58:38Z 2021-04-11T18:10:20Z plotting logarithmic and linear scale I'm working on an assignment that wants me to create a .m file that graphs both the linear and logarithmic scale. The assignment is: I have the script doing exactly what I need it to for the linear scale plot, however, I'm not sure how to also get matlab to transition it to log scale for the second set of plots. any help would be useful. The code I have so far is: t=linspace(0,20,1000); speed=188.5*(1-exp(-0.4*t)); torque=10*exp(-0.4*t); power=torque.*speed; figure(1) subplot(3,1,1) plot(t,torque,'r-','LineWidth',2) title('\bfPlot of Motor Output Torque\bf\it\tau\rm\bf_{IND},Speed\bf\it\omega_{m},and Power\bf\itP vs Time') ylabel('\bf\itTorque, \tau\rm\bf_{IND}(N-m)') grid on subplot(3,1,2) plot(t,speed,'r-','LineWidth',2) ylabel('\bf\itSpeed, \omega_{m}\rm\bf(rad/s)') grid on subplot(3,1,3) plot(t,power,'r-','LineWidth',2) xlabel('\bfTime,t[s]') ylabel('\bf\itPower, P\rm\bf(watts)') grid on the plots of the log scale should look like this: Brendan Clark https://www.mathworks.com/matlabcentral/profile/authors/21223451 tag:www.mathworks.com,2005:Question/796442 2021-04-08T15:15:36Z 2021-04-11T18:09:31Z Read date and version number from txt file via regular expression Hi, my task is to read version of software and date of the usage from a log file. Version number appears on a row like this: Version 2.85; and date on a row like: Date of elaboration : 26-Mar-2021 12:54:25; I'm able to split the txt file that contains the log onto rows, i only need to extract "2.85" and "26-Mar-2021" via Regular expressions. Thanks for your time, Alessandro Alessandro Togni https://www.mathworks.com/matlabcentral/profile/authors/20843104 tag:www.mathworks.com,2005:Question/799082 2021-04-11T18:05:13Z 2021-04-11T18:05:13Z Thermal modelling of a photovoltaic module in simulink Hello, I am a master student and have a question for the community. I should create a thermal model of a photovoltaic module in simulink. I'd be glad if I can contact someone who already created one before and help me. I haven't used simulink before. metin elgin https://www.mathworks.com/matlabcentral/profile/authors/21248163 tag:www.mathworks.com,2005:Question/799077 2021-04-11T18:03:53Z 2021-04-11T18:03:53Z Connecting jetson nano with Pixhawk I have been trying to connect the Jetson nano device to Pixhawk to obtain the roll, pitch and yaw values. I am following the instructions as per the link https://www.mathworks.com/help/supportpkg/jetsoncpu/ref/jetson-pixhawk-interface-example.html?searchHighlight=jetsoncpuLib&s_tid=srchtitle. Currenlty, I am stuck at the task 4(of the link provided) which is to perform monitor and tune. The yaw, pitch and roll value changes during tune under the target model, but not running during the simulation of the Jetson Pixhawk Interface Host model and gives error. Dhruvil Vekariya https://www.mathworks.com/matlabcentral/profile/authors/17369502 tag:www.mathworks.com,2005:Question/799062 2021-04-11T17:52:30Z 2021-04-11T17:56:40Z Find baseline and sudden signal changes (as well as duration until return to baseline) for noisy data I'm struggling with some data I extracted and hoping for some help on how to best deal with it. I have attached an example The presumed baseline is marked in red. I have multiple consecutive events indicated by a sudden change in baseline and then becoming weaker over time before changing back to basline. I would need the length of such an event. How can I best determine the baseline and relaibly measure the lengths of these events. Hope someone can give me some directions Lutetium https://www.mathworks.com/matlabcentral/profile/authors/20037566 tag:www.mathworks.com,2005:Question/798602 2021-04-11T04:46:16Z 2021-04-11T17:54:54Z why my plot is not correct? here is my code x = -5:0.1:5 y = x.^(1/3) plot(x,y) wenchong chen https://www.mathworks.com/matlabcentral/profile/authors/18123326 tag:www.mathworks.com,2005:Question/791729 2021-04-03T16:35:45Z 2021-04-11T17:54:15Z Calculate diameter from a circle in an image in MATLAB Hi, I have to measure the diameter from a circle in a image and I don't quite know where to start. I began by loading the image and turning it into a blacknwhite image. img = imread (file); labimg = rgb2lab(img); Now I basically need my program to detect the circle and measure the diameter. and then plot it I really hope someone could help me out Thanks a lot songül bagbars https://www.mathworks.com/matlabcentral/profile/authors/16602801 tag:www.mathworks.com,2005:Question/705683 2020-12-30T18:43:32Z 2021-04-11T17:47:41Z Very slow graphics when mouse pointer moves around a figure I've got a little widget that animates a sequence of images by calling the "image()" function repeatedly with new images in a sequence. Normally the animation proceeds reasonably fast around 50-60 frames per second. However, if the mouse is in the figure window and moves around (not even clicking on anything), then the animation slows to a crawl (about 2-3 frames per second) as long as the mouse moves in the figure window. (See code at bottom for simple example to replicate this). I've checked to ensure that the 'WindowButtonMotionFcn' figure callback is disabled (as are all other figure callbacks). I can't find any other figure, axes or even image objects that might be triggered by mouse motion in the figure window. If I run the profiler and compare results with and without the mouse moving around the figure window, I see the function: ToolbarController.ToolbarController>@(e.d)obj.handleMouseMotion (and its dependent functions ) is getting called thousands of times and is consuming 90% of the runtime when the mouse is moving around I tried turning off both the figure's toolbar and the figure's menu bar, e.g: hFigure.ToolBar = 'none'; hFigure.MenuBar = 'none'; and that slightly alleviates the issue somewhat, but not much (perhaps 10-20% better) . Further, even with the toolbars turned off, the profiler still indicates that ToolbarController.ToolbarController>@obj.handleMouseMotion is still consuming 90% of the run time whenever the mouse is moving around. There also is the function AxesToolbarButton.AxesToolbarButton>AxesToolbarButton.AxesToolbarButton that is also getting called thousands of times and is consuming some of the time. So I also disable the AxesToolbar by: axesTB = get(hAxes,'ToolBar'); axesTB.visible = 'off'; axesTB.BusyAction = 'cancel'; (Unlike the figure toolbar, there doesn't seem a setting to completely disable a AxesToolbar). Anyway, turning off the axesTB didn't seem to help. % This code can be used to illustrate the issue of slowly updating graphics. % Run this, and then move the mouse around the figure window. for loop=1:500 image(rand(300,300),'CDataMapping','scaled'); drawnow; end %Clearing the axes with "cla" before the image() call doesn't change the result. However, this version of the code is seemingly NOT impacted by this issue or very little: hImg = image(rand(300,300),'CDataMapping','scaled'); for loop=1:500 hImg.CData = rand(300,300); drawnow; end In the latter case, the profiler say that the function ToolbarController.ToolbarController>@(e.d)obj.handleMouseMotion still gets called a whole bunch of times but it ends up only consuming about 15% of the runtime (not 90+%), and the animation proceeds at 50+ FPS. So there is something about the combination of a moving mouse and creating new objects (rather than changing attributes of existing objects) that seems to grind matlab graphics to a halt. While I clearly point out a workaround for my little example above, in the general case, such workarounds are not always possible. It seems odd that moving a mouse while drawing objects in a figure shouldn't necessarily slow down things as much as it appears to do. Thoughts appreciated. Peter https://www.mathworks.com/matlabcentral/profile/authors/14174 tag:www.mathworks.com,2005:Question/798747 2021-04-11T10:51:26Z 2021-04-11T17:46:59Z How to change values to 3 decimal points and 7 significant figures? hi, I am Matlab program beginner. I came across a problem in which I want to change the decimal places and significant figues of the value I computed. The values I get is easting_northing = 1.0e+03 * 1.0000 1.0000 1.0635 0.9227 but actually I need the values to become like this form: easting_northing = 1000.000 1000.000 1063.500 922.720 how to do that??? thank you in advance Loh Yang Yau https://www.mathworks.com/matlabcentral/profile/authors/21964682 tag:www.mathworks.com,2005:Question/798967 2021-04-11T16:19:09Z 2021-04-11T17:43:57Z plotting line graph in different colors using while loop I have a variable called "data" that's a set of data that's 49 rows x 40 columns. time is the first column (data(:,1)) and I want to plot time against the second column of the data (data(:,2)). When the the values in the second column are in certain ranges, I want the line of the line graph to be different colors. I wrote a while/ if else statement to do this, but it's not plotting anything and I'm not sure why. My code is written below. Thank you in advance! figure p = 1 %row that's changing (40 rows in all) w = 2 %sensor/column number hold on while p <=size(data,1) %size of column if data(p,w)<2.65 plot(data(p,1),data(p,2),'g') elseif data(p,w)>=2.65 & data(p,w)<3.975 plot(data(p,1),data(p,2),'y') else data(p,w)>=3.975 plot(data(p,1),data(p,2),'r') end p = p+1 end Lauren Yeary https://www.mathworks.com/matlabcentral/profile/authors/10832534 tag:www.mathworks.com,2005:Question/788529 2021-03-31T00:14:24Z 2021-04-11T17:43:39Z Why is my priceandvol chart not showing all the values? how do i label the price chart and the volume chart? how do i get dates on the price chart? clear clc walmart = xlsread('WMT_Daily_Returns3.xlsx'); dateconvert=x2mdate(walmart, 0, 'datetime'); priceandvol(walmart(:,2:end)); xlabel('Date') ylabel('Volume') dateaxis('X', 12, min(walmart(:,1))) title('Walmart Stock Price and Volume') legend('Volume of Shares') Matty O'Malley https://www.mathworks.com/matlabcentral/profile/authors/21222395 tag:www.mathworks.com,2005:Question/799052 2021-04-11T17:42:43Z 2021-04-11T17:42:43Z configurePlutoRadio('AD9364','usb:0') Command not working I am trying to configure my new ADALM PLUTO SDR to the AD9364 configuration in order to be able to get the bigger frequency range. I want to receive signals at 150MHz which should be fine after using the >> configurePlutoRadio('AD9364','usb:0') command. I ran the command and it showed me that the configuration is successful. However, I still get an error about operating outside the factory default frequency range for the SDR and I get prompted to run the same command and I run it again but still get the same error. This is the error I keep on getting: Failed to update LO for device: cf-ad9361-lpc. Specified center frequency is outside factory default range. To assign the center frequency to 150000000, release the radio and click configurePlutoRadio('AD9364','usb:0'). For more information, see help configurePlutoRadio. Is the command outdated and does not work anymore or am I doing something wrong? Looking forward for a reply. Thanks. rashed alhaj mohammad https://www.mathworks.com/matlabcentral/profile/authors/14859404 tag:www.mathworks.com,2005:Question/799032 2021-04-11T17:27:08Z 2021-04-11T17:27:46Z Simulation of Shepp Logan phaton dataset What is the name of the method used for the simulation of Shepp Logan phantom having dimention 256x256 with number of coils=8. Ria khan https://www.mathworks.com/matlabcentral/profile/authors/22166896 tag:www.mathworks.com,2005:Question/799012 2021-04-11T16:52:27Z 2021-04-11T17:25:55Z interp1 question for resampling I am trying to use interp1 to resample my data. I have the values of forces for different timeframe lengths. (eg. I have 4 trials, trial one has 36 frames, trial 2 has 43, trial 3 has 38, tria4 has 35). To compare them have a nice figure, I want to <<expand>> the number of frames to 100 for each of them (like it would be 1-100% of the timeframe). I used resample in the beginning, but I get some noise in the beginning and the end of the signal. dif_Fx = (resample(dif(1:motion_length,1),100,motion_length)) (motion_length is the number of frames and dif is my signal) I tried to use interp1 as dif_Fx = (interp1((dif(1:motion_length,1)),1:1:100)); dif_Fx is just the signal (dif), and the rest of the values, from motion_length+1 to 100 are NaN. I have read again and again the documentation, but I can;t seem to understand how to modify it to get what I want. Any help is much appreciated. Andra Topan https://www.mathworks.com/matlabcentral/profile/authors/11249921 tag:www.mathworks.com,2005:Question/799027 2021-04-11T17:24:32Z 2021-04-11T17:24:32Z Method for Shepp Logan Phantom What is the method used to estimate Shepp logan dataset of size 256x256 with 8 number of coils. Ria khan https://www.mathworks.com/matlabcentral/profile/authors/22166896 tag:www.mathworks.com,2005:Question/465444 2019-06-04T08:50:00Z 2021-04-11T17:21:33Z Please write the code for this question. Given a Matrix A, Create a row vector of 1's that has same number of elements as A has rows. Create a column vector of 1's that has the same number of elements as A has columns. Using matrix multiplication, assign the product of the row vector, the matrix A, and the column vector (in this order) to the variable result. A = [1:5; 6:10; 11:15; 16:20]; Gaurav Srivastava https://www.mathworks.com/matlabcentral/profile/authors/13163632 tag:www.mathworks.com,2005:Question/799022 2021-04-11T17:19:28Z 2021-04-11T17:19:28Z MATLAB program for the design of Chebyshev digital low pass filter using Write a MATLAB program for the design of Chebyshev digital low pass filter using the following specification: 0.9 ≤│H(ejw)│≤ 1 0 ≤ w ≤ 0.3π │H(ejw)│≤ 0.15 0.5π ≤ w ≤ π Nishant k https://www.mathworks.com/matlabcentral/profile/authors/20964689