Legend for matrix plot

Hi. I have 3 matrixes. The first one contains measured frequencies:

   freqs =
   5   6   7

For each frequency I have x and y values:

x =

    0.0116    0.0106   -0.0335
    1.0986    1.0385    0.9020
    2.0674    1.9955    1.9334
    2.9450    3.0869    3.0334
    4.0941    3.9551    4.0341
    4.9456    4.9273    4.9743
    6.0086    5.9592    6.0323
    6.9813    7.0303    7.0465
    7.9971    8.0223    8.0208
    9.0282    8.9445    8.9044
   10.0000    9.9224   10.0955

y =

   -292  -286  -299
   -283  -277  -295
   -274  -267  -292
   -266  -256  -285
   -254  -245  -278
   -244  -238  -272
   -232  -227  -259
   -224  -218  -249
   -215  -210  -239
   -208  -204  -231
   -202  -199  -219

And to plot y vs x for each frequency i simply do:

p=plot(x,y)

which returns

      p = 

    3x1 Line array:

Line
Line
Line

This plot is exactly as how like it. Now however. I can't put a legend here. For instance

legend('f1=5','f2=6','f3=7')

Returns the error:

Index exceeds matrix dimensions.

What can I do? It feels like I have tried everything..

[Adam]

This works fine for me. Do you have a variable with the name 'legend' that is hiding the function?

What does

which -all legend

show?

[Björn Persson]

It showed a variable, I removed it and now everything works. Thanks! I must have made a variable by mistake during debugging, and it caused me quite a lot of pain. Great that you could identify it!

[Adam]

I will add my comment as an answer then in case it helps anyone else too.

Answer 1

[Adam]

This works fine for me. Do you have a variable with the name 'legend' that is hiding the function?

which -all legend

will show if this is the case. Then removing the variable will allow the function to be 'seen' again and all should work fine.

Try to make sure you never name variables after builtin functions. If you are unsure when naming a variable you can always use the 'which' command e.g.

which size

if you were considering to name a variable 'size'. then you will see this is a bad idea as it will show up a function of this name. Equally you should not name variables the same as your own functions for the same reason.