Question

Different commands to do spline interpolation, are they the same?

Hello, I have a question about (cubic) spline interpolation in MATLAB. For cubic spline interpolation I see several commands wh...

6 months ago | 1 answer | 0

Question

More detailed output function in optimization

Hello, I think I have a simple question but found it difficult to fix it myself. In doing the optimization we can have 'our' ...

6 months ago | 0 answers | 0

Question

Choosing a function handle from a group of function handles

Hello, Assume that we have saved many function handles f_1_1, f_1_2,f_1_3, ..., f_2_1,f_2_2,f_2_3, .... in a folder. Now, assum...

6 months ago | 1 answer | 0

Question

Matlab function with initial long execution time

Hello, When I run a function handle its execution time is initially very long but in the second, third, etc runs its execution ...

7 months ago | 1 answer | 0

Question

Conversion from symbolic to matlabFunction and writing the result to a file

Hello friends, I have a simple problem but it seems difficult for me to fix. I want to create a matlabFunction from a symboli...

7 months ago | 1 answer | 0

Question

Techniques of common subexpression elimination, disorganization in MATLAB, etc..

Hello friends, Yesterday I posed a question about performance gain in matlab by using techniques of common subexpression elimin...

7 months ago | 0 answers | 0

Question

My mex file is slower than my original matlab equivalent

Hello friends, I need to calculate some quantities of linear algeibra type, so they are merely matrix and vector products. The ...

7 months ago | 1 answer | 0

Question

If matlab coder fails can we still do it ourselves?

Hello friends, I have a simple question. As you know matlab coder cannot create mex functions always, for instance when the inp...

7 months ago | 1 answer | 0

Question

Making a mex function for a rather complex code

Hello friends, I have a code which is very time consumming. Therefore, I thought to use mex function to do the heavy part of ca...

7 months ago | 0 answers | 0

Question

Defining complex input types to make a complex mex function

Hello friends, Recently I became familliar with mex function. I am quite new to this and have lots of hopes to speed up my slow...

7 months ago | 0 answers | 0

Question

Finding the index of elements of a vector in a mesh quite fast

Hello friends, I would like to find the index of vector of numbers A being closest in a mesh. I know how to do this but I hope ...

8 months ago | 1 answer | 0

Question

Difference between spline(x,y,xq) and interp1(x,y,xq,'spline')

Hello friends, I have a simple question. I am wondering what is the difference between the commands spline(x,y,xq) and interp...

8 months ago | 2 answers | 0

Question

Indefinite integral for a step function with variable number of steps

Hello friends, I have a function handle which is defined by interp1. Is there a way to find its indefinite integral? For inst...

8 months ago | 1 answer | 0

Question

Step function with variable number of steps

Hello friends, I have a simple question but would like to find an efficient way to implement it for my very heavy codes. Assume...

8 months ago | 1 answer | 0

Answered

Quadratic spline having shape preserving property

Hello John, I did not know that a shape preserving quardatic spline cannot be smooth at breaks. Yes, I agree with you that I ...

Quadratic spline having shape preserving property

Hello John, I did not know that a shape preserving quardatic spline cannot be smooth at breaks. Yes, I agree with you that I ...

8 months ago | 0

Question

Quadratic spline having shape preserving property

Hello friends, In my work I need to use quadratic splines and I can use the command spapi(3,x_data,y_data). Unfortunately, I ...

8 months ago | 2 answers | 0

Question

Multivariate Horner scheme implementation in MATLAB

Hello friends! I have very long symbolic expressions (mainly polynomials or rational types) and I need to evaluate them man...

11 months ago | 0 answers | 0

Question

PP form for the reverse function (not inverse function)

Hello friends! Consider a pp form for a set of (x,y) data points. Imagine now that we wish to find the pp form for the (x,1/y) ...

12 months ago | 0 answers | 0

Question

Find constants in a symbolic vector

Hello friends! I have a simple question but found it difficult to come up with a perfect answer. I explain by a simple example....

12 months ago | 1 answer | 0

Question

Suitable input for a function handle

Hellow friends, I need to do something which I explain through a simple example. Consider the following F=@(x,y,z)[x.*z.^2.*y;...

1 year ago | 1 answer | 0

Question

I cannot remove 0 elements of a symbolic array

Hello friends! Consider the following commands syms x sigma(x) par=sym('par%d', [1 2],'positive'); sigma(x)=par(1)+par(2)*...

1 year ago | 1 answer | 0

Question

Replace powers with a sequence

Hello friends! Consider a binomial symbolic expression like (x-1)^3 and a symbolic vector e of size 3 (e=sym('e',[1 3]) ). Of ...

1 year ago | 1 answer | 0

Question

Subs does not do the job

Hello friends! I do not understand why in my code (see bellow) the command 'subs' does not through ant error and at the same ti...

1 year ago | 1 answer | 0

Question

Perhaps a bug in matlab?

Hello friends! I think I have encountered a bad issue about matlab, perhaps it is a bug. Consider the following commands >> sy...

1 year ago | 1 answer | 0

Question

PP form for griddedInterpolant

Hello friends! This morning I was going to use interp1 but noticed that matlab is going to remove it soon. Instead, they recom...

1 year ago | 1 answer | 0

Question

Vectorizing a function handle with some constant inputs

Hello friends! I have an annoying problem and need your kind help! Suppose that I have a symbolic vector like f = [x+y;0;x.*y;...

1 year ago | 0 answers | 0

Question

How to turn a function handle with 3 inputs (1 variable and 2 parameters) and then assign the inputs parameters and get a function handle with one input? ?

Hello friends! Consider the following y=1;z=1; f=@(x,y,z)x+y+z; Now, I would like to create another function handle which is...

1 year ago | 3 answers | 0

Question

A very strange problem

Hi friends! After spending an hour on a seemingly simple problem I was not able to figour out what is wrong and this is why ...

1 year ago | 3 answers | 0

Question

A simple algebraic which I failed to do

Hello friends! Unfortunately, I have to tell you that I am unable to do a simple math I learned at intermediate school in mat...

1 year ago | 1 answer | 0

Question

How to tell vpa command to consider digits after decimal point' only?

Hello friends, I have a simple question, I think! I have a symbolic expression S with numeric coefficients. I need to round the...

1 year ago | 1 answer | 0