Error using fplot: Warning: Error updating FunctionLine.

Hi everyone,

I would like to plot the following function:

function ax_max = maxax(ay,v)

    if (v <=130/3.6)
    ax_max(ay <= 0.8) = -3.5;
    ax_max(ay > 0.8 & ay <= 4.5) = -307/74 + 30/37*ay;
    ax_max(ay > 4.5) = 0;
    else
    ax_max(ay < 0.5) = -2.5;
    ax_max(ay >= 0.5 & ay <= 2.5) = -25/8 + 5/4*ay;
    ax_max(ay > 2.5) = 0;
    end
    ax_max=abs(ax_max); 
end

by using

fplot(@(ay) -maxax(ay, sqrt(30*ay)), [0 5])

I would like to create four subplots varying the number "30" fplot (30, 123, 400, 900). The fplot function works wenn using "900", but with for example "30"I just get an empty plot and the following warning:

"Warning: Error updatin Function Line. The following error was reported evaluating the function in FunctionLine update: In an assignment A(:) = B, the number of elements in A and B must be the same."

Thank you for your help!

[Anurag Agarwal]

Sir,

Did you get the solution of it? If yes, please share.

Answer 1

[HUXIN GAO]

Hello! Recently I have encountered the same problem. Have you solved it? if done, could share it with me. Thanks very much!

[madhan ravi]

Ask a question separately @ Huxin with all the necessary details

[Anurag Agarwal]

@Huxin Gao, did you get the solution? If yes, please share it.

Thank you

Answer 2

[Walter Roberson]

V = [30, 123, 400, 900];
nV = length(V);
for K = 1 : nV
    subplot(1,nV,K)
    fplot(@(ay) -maxax(ay, sqrt(V(K)*ay)), [0 5]);
    title(sprintf('V = %f', V(K)));
end