Plot several lines (looping through line styles in cell array) in Matlab

问题

I have written this loop to plot each line of results and I get the error message

Error using plot. Invalid first data argument.

So far it looks like this

test=rand(5,6);
xint=[1:1:6];
LineSpec = {'-y', '--m', ':c', '-r.', '-b', ':s'};

for ii=1:5,
    plot(xint,test(ii,:),LineSpec(ii),'linewidth',2);
    hold on;
    legend_str{ii} = num2str(ii);
end

If I use plot(xint,test(ii,:),'-y','linewidth',2) then it works. But how can I avoid the error when looping through line styles?

回答1:

You should write:

plot(xint,test(ii,:),...
        LineSpec{ii},...
        'linewidth',2);

LineSpec is a cell array, so LineSpec(ii) returns a cell, while plot asks for a character array as line properties.

you can see the difference when you call LineSpec:

>> LineSpec{1}
ans =
-y
>> LineSpec(1)
ans = 
    '-y'

When the output is a cell then the answer is indented and has the single-quote marks.

来源：https://stackoverflow.com/questions/44107503/plot-several-lines-looping-through-line-styles-in-cell-array-in-matlab