Error trying to define an output function

Hello to everybody!! I can't understand how to correctly define an output function. I tried to define a function which plot the histogram of residuals on each iteration on this way:

function stop=his(x,optimValues,state)
stop=false;
switch state
    case 'init'
        figure
        title('residual_plot')
    case 'iter'
    plot(histogram(optimValues.residual,15))  
    otherwise
end

But I recived this error:

Error using plot
Not enough input arguments.

Error in his (line 8)
    plot(histogram(optimValues.residual,15))

I used lsqnonlin with 'OutputFcn' option.

I hope somebody could help me. Thanks

Answer 1

[Steven Lord]

The histogram function creates its own graphics object. There's no need (and indeed it shouldn't work) to pass a histogram handle into plot.

Note that as your code is written, creating a histogram at each call to the output function with the 'iter' flag will clear the histogram from the previous iteration since you haven't turned hold on. Is that what you want to do?

[MtPt]

Thanks, now it works! I thought it could show me histograms "dynamically" during iteration, but it doesn't work. I will search other solutions. I thank you for the answer

Answer 2

[Image Analyst]

I don't know what the purpose of stop is. You don't even use it, and you shouldn't even use it because it's a built-in function that stops the time.

histogram does the plotting by itself, so don't pass it to plot(). Just call it:

histogram(optimValues.residual, 15);
grid on;

You should fancy it up by setting xlabel and ylabel, you can set the bar color, and the bar edge color and bar width, etc.

[MtPt]

I know I have learnt it after sending my question