This is a modified version of the function quiver [from C.M. Thompson] to plot velocity vectors as arrows with components (u,v) at the points (x,y) with the color corresponding to the magnitude of the vector and using the current colormap.
Tip: for best results, add set(gcf, 'InvertHardCopy', 'off') after the function to keep the black background on the hardcopy. See attached examples.
Bertrand Dano (2021). Quiverc (https://www.mathworks.com/matlabcentral/fileexchange/3225-quiverc), MATLAB Central File Exchange. Retrieved .
@ Pablo Encinas: To get the classic white background, you can change line 174 and 175 of the function to:
set(gca, 'color', [1 1 1],'Xcolor','k','Ycolor','k');
set(gcf, 'color', [1 1 1]);
@ Bertrand Dano: good work!
@ Robert, not much I can do without the code you used and reach this error.
Try this. If it works, the problem is not quiverc.
clear all; close all; clc
Getting this ???
Undefined function or variable 'h1'.
Error in quiverc (line 173)
if nargout>0, hh = [h1;h2;h3]; end
Error in L_Transport2 (line 129)
My background is black, how can I change it to classic white?
how can I show the corresponding color scale bar on the side of the plot?
I was able to fix it.
This is just great thanks!
This is awesome. However i tried to look into it to get a '3D' version, like quiver3 as Joe posted june 2013. Does it exist?
Hi Dano, this is a great code! Is there a variation of this code of this using 3D data (similar to quiver3)? Thanks
I have this error when I run the codes， too.
I already found the problem. My code had colormap(gray(2)) before the plot.
??? Attempted to access CC(5,1); index out of bounds because size(CC)=[2,3].
Error in ==> quiverc at 134
c1= CC(ii,1); c2= CC(ii,2); c3= CC(ii,3);
I have this error when I run the codes. C(x,1) x is alwyas different and bigger than 2. Anyone can help me??
good job, but one comment: when I use h=quiverc(x,y,U,V,S), it seems the code can not return h? In other words, quiverc(x,y,U,V,S) works, but h=quiverc(x,y,U,V,S) does not work.
Great file, thanks! But -- is there any way to use quiverc.m to create a colour quiver plot, but with all arrows plotted with same lengths? I.e. magnitude of vectors to be indicated solely by color and not length. It's redundant to indicate magnitude both by length and color; moreover, some vectors are often so small (relative to others in the field) that they are "invisible", in which case the colormap is useless anyway. Thanks.
I am using your cool code quiverc for plotting velocity fields that evolve over time In your code you normalize colormaps so that red in colorbar refers to max velocity with in frame I am trying have a global colormap where I insert max value velocity value within my frames so red refers to this value at all times
I tried to change max(vr(:)) in code below with my global max value but it does not work
ax = newplot;
next = lower(get(ax,'NextPlot'));
hold_state = ishold;
Do you have an idea how I can go around this ?
Thanks in advance
Thanks! This is very useful.
Excellent, except that the color mapping is incorrect if the current colormap is longer than 64. Changing the two int8 calls in quiverc to int16 fixes this problem.
It's a very useful tool for ploting! Thanks!
Brilliant and extremely useful! Thanks!
great job, save me much time to write code
Not as fast as quiver for large vector/velocity field. But fine otherwise.
I was working with quiver plots to show current velocity and direction from a moving vessel. The quiverc is perfect for creating a figure that is easy to qualitativy interpret.
I find the output of quiverc easier to interpret than that of quiver. My only qualm is that it runs a bit slow with the data I am plotting -- I wan't to show a sequence of quiver plots. Also it doesn't seem to handle NaNs in the data automatically (just replace them with 0s)
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