How to add axis labels while using for loops? Keep getting error: Index exceeds the number of array elements (4).

6 次查看（过去 30 天）

Kendall Noto 2020-1-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/501002-how-to-add-axis-labels-while-using-for-loops-keep-getting-error-index-exceeds-the-number-of-array

编辑： Adam Danz 2020-1-19

I am getting an error trying to add axis titles to my plot. I am using a for loop, but it is only letting me add a legend and a title.

this is the error message:

Index exceeds the number of array elements (4). Error in Homework_1 (line 12) xlabel('real')

z = [2 + 5i; 1.41+1.41i; 5.87+9.15i; -3.07+6.72i; 0.997+0.071i; 3*exp(1.23i); 2*exp((pi/2)*1i); 13*exp(1i); 3; 2+11i; 4+2i; (1/5)+(4/5)*1i;  ] ;
s = ['o'; '*'; 's'; 'p'; '+'; '>'; '<'; 'x'; 'd'; '.'; 'h'; '^';];
for index = 1:12
    plot (z(index), s(index), 'MarkerSize', 10 );
    hold on;
   
end
hold off;
title('complex numbers');
legend('2 + 5i', '1.41+1.41i', '5.87+9.15i', '-3.07+6.72i', '0.997+0.071i', '3*exp(1.23i)', '2*exp((pi/2)*1i)', '13*exp(1i)', '3', '2+11i', '4+2i', '(1/5)+(4/5)*1i');
xlabel('real');
ylabel('imaginary');

2 个评论
显示无隐藏无

woahs 2020-1-19

Not sure what the issue is here. The provided code executes without error. Your axis properties are set outside the loop so the fact that you used a loop to create them shouldn't matter.

Kendall Noto 2020-1-19

when i run this script is does not add the labels to my resulting plot

while giving me this error message:

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Adam Danz 2020-1-19

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/501002-how-to-add-axis-labels-while-using-for-loops-keep-getting-error-index-exceeds-the-number-of-array#answer_410920

编辑：Adam Danz 2020-1-19

在 MATLAB Online 中打开

Updated answer

It appears that you may have a variable named xlabel that is interfering with the xlabel() function. To confirm this, run the line below.

which xlabel

If my hunch is correct, it should output: xlabel is a variable.

-----------------------------------------------------------------------

Old answer (still relevant)

As Kevin Chen mentioned, the code you shared does not result in any errors.

Here are 3 improvements to make.

Define number of iterations based on number of values available
Use DisplayName to label the legend

z = [2 + 5i; 1.41+1.41i; 5.87+9.15i; -3.07+6.72i; 0.997+0.071i; 3*exp(1.23i); 2*exp((pi/2)*1i); 13*exp(1i); 3; 2+11i; 4+2i; (1/5)+(4/5)*1i;  ] ;
s = ['o'; '*'; 's'; 'p'; '+'; '>'; '<'; 'x'; 'd'; '.'; 'h'; '^';];
% Define legend strings
legStr = {'2 + 5i', '1.41+1.41i', '5.87+9.15i', '-3.07+6.72i', '0.997+0.071i', '3*exp(1.23i)', '2*exp((pi/2)*1i)', '13*exp(1i)', '3', '2+11i', '4+2i', '(1/5)+(4/5)*1i'};
for index = 1:numel(z) % use z or s
    plot (z(index), s(index), 'MarkerSize', 10, 'DisplayName',legStr{index}); % use DisplayName
    hold on;
end
hold off;
title('complex numbers');
legend(); % just call legend()
xlabel('real');
ylabel('imaginary');

You could also move "hold on" outside of the loop.

8 个评论
显示 6更早的评论隐藏 6更早的评论

Kendall Noto 2020-1-19

Ohhh, i do remember now that i entered the xlabel wrong when i tried to do it at the very beginning. I understand now. Thank you so much for your help!!!

Adam Danz 2020-1-19

编辑：Adam Danz 2020-1-19

One way to avoid these types of errors is to use functions rather than scripts. Functions have their own workspaces so if you accidentally created a variable named xlabel from the command window, it wouldn't exist within the function workspace the next time the function was run.

https://www.mathworks.com/help/matlab/matlab_prog/scripts-and-functions.html

请先登录，再进行评论。