too many output arguments when calling axis in cellfun

Hi there!

I want to use cellfun to plot figure for each element of the cell C3.

The code is:

cellfun(@(x,i){...

figure(i);...

set(gcf,'Position',[400*(i-1),50,400,300], 'color','w');...

fill(real(x),imag(x),[1,0.75,0],'EdgeColor','None');...

axis(gca,'equal','off')},...

C3,num2cell(1:length(C3)),'UniformOutput',false);

The error occurs: too many output arguments.

The problem come from

axis(gca,'equal','off')

It has no output argument.

So how to use cellfun to plot figure and modify its axis?

I know I could use for loop to plot, but the one-line code is cool.

By the way, code of this form seems difficult to fit into a one line code

axis equal off

Answer 1

[Stephen23]

"It has no output argument."

Yes, it does. Every expression inside the curly-braces is evaluated and its output is requested. With the exception of comma-separated lists, every expression must provide one output.

"I know I could use for loop to plot..."

Avoid the anonymous function with CELLFUN. Either:

• use a FOR-loop and call the code directly, or
• use a local/nested function and CELLFUN.

"By the way, code of this form seems difficult to fit into a one line code"

Command-syntax is really just a convenience in the command window. Otherwise it is best avoided.

Answer 2

[Walter Roberson]

The code sequence

@(x,i){...
    figure(i);...
    set(gcf,'Position',[400*(i-1),50,400,300], 'color','w');...
    fill(real(x),imag(x),[1,0.75,0],'EdgeColor','None');...
    axis(gca,'equal','off')}

is not equivalent to executing the individual functions at the command line or as individual commands. MATLAB does not have "code blocks" like C or C++ does. {A; B} does not mean to designate a series of statements to be executed.

Instead, {} is the cell-array constructor. Each entry is to be evaluated, and the (first) return output from the command is to become the value of the corresponding cell entry. So

{...
    figure(i);...
    set(gcf,'Position',[400*(i-1),50,400,300], 'color','w');...
    fill(real(x),imag(x),[1,0.75,0],'EdgeColor','None');...
    axis(gca,'equal','off')}

is like

temp1 = figure(i);
temp2 = set(gcf,'Position',[400*(i-1),50,400,300], 'color','w');
temp3 = fill(real(x),imag(x),[1,0.75,0],'EdgeColor','None');
temp4 = axis(gca,'equal','off');
output = {temp1, temp2, temp3, temp4};

If any of the statements do not (cannot) return a value, then you would get an error.