What is the problem with legend?

Here is a snippet of my code:

clc;
figure
 x=[30.423 32.562 33.356 34.892];
x1=[30.63 32.822 33.556 34.893];
x2=[30.83 32.962 33.856 34.895];
 y=[0.004 0.003 .002 .001];

 axis([20 45 1 4])
plot(y,x,'-bo',y,x1,'g-*',y,x2,'-k^','linewidth',1.5,'markeredgecolor','r')
xlimit=[20 40];
xlabel ('Noise level(salt & pepper)');
ylabel ('PSNR');
 legend('plain image','cipher image');

It shows output as this error when it hits line 54 of my code:

Error using legend (line 278)

Attempt to execute SCRIPT flip

as a function:

C:\Matlab\bin\R2020a\bin\matlab\flip.m

Error in entropy_graph (line 54)

legend('plain image','cipher

image');

[Les Beckham]

Can you tell us what you see if you type this command at the Matlab prompt?

which -all flip

I suspect that you have created a script called flip.m that is somewhere on your path (probably in C:\Matlab\bin\R2020a\bin\matlab\flip.m where there is normally no flip), or in the current working directory. You should rename it since flip is a Matlab function and (apparently) is used by the legend function.

[Parveiz Lone]

thanks a lot, i delete the file and create a new file with a different name it works

Answer 1

[Walter Roberson]

C:\Matlab\bin\R2020a\bin\matlab\flip.m

Is not a flip.m supplied by Mathworks. flip is a built-in in your version, with a typical "which" location of

C:\Program Files\MATLAB\R2020a\toolbox\matlab\elmat\flip

You might need to reinstall MATLAB completely.

Answer 2

[Image Analyst]

I just copied and pasted and it works fine:

clc;
figure
 x=[30.423 32.562 33.356 34.892];
x1=[30.63 32.822 33.556 34.893];
x2=[30.83 32.962 33.856 34.895];
 y=[0.004 0.003 .002 .001];

 axis([20 45 1 4])
plot(y,x,'-bo',y,x1,'g-*',y,x2,'-k^','linewidth',1.5,'markeredgecolor','r')
xlimit=[20 40];
xlabel ('Noise level(salt & pepper)');
ylabel ('PSNR');
 legend('plain image','cipher image');

The error must lie somewhere in the intervening 50 lines you did not show us.