Plot data in loop with num2str

8 次查看（过去 30 天）
yoni verhaegen
yoni verhaegen 2018-7-23
评论： Stephen23 2018-7-24
Hi all,
I want to plot a dynamic figure by plotting the sixth column of the datasets Meteo1752 to Meteo1966:
balyr=1752;
endyr=1966;
for k = balyr:endyr
balanceyear(k-balyr+1,:)=k;
plot(['Meteo' num2str(k) '(:,6)']);
end
However, the error says
Error using plot
Invalid first data argument.
What am I doing wrong?
Thanks
  2 个评论
Adam
Adam 2018-7-23
编辑：Adam 2018-7-23
doc plot
tells you what the valid data types are for the inputs. plot expects numeric data arguments (or an axes handle as first argument). You are giving it a string.
You'll have to give your actual data to the plot instruction, and probably you will need to use
doc hold
too.
Stephen23
Stephen23 2018-7-24
@yoni verhaegen: what you are trying to do is not recommended. Read this to know why:
https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval
It is easy to avoid this situation: usually some indexing is the key.

请先登录，再进行评论。

请先登录，再回答此问题。

回答（2 个）

Dimitris Kalogiros
Dimitris Kalogiros 2018-7-23
If you want to display something on your workspace, use disp() instead of plot()
balyr=1752;
endyr=1966;
for k = balyr:endyr
balanceyear(k-balyr+1,:)=k;
%plot(['Meteo' num2str(k) '(:,6)']);
disp(['Meteo' num2str(k) '(:,6)']);
end
dpb
dpb 2018-7-23
编辑：dpb 2018-7-23
Several things...the specific error is trying to plot() a string; ML will not do character substitution like that.
The more fundamental issue is in having created the multiple variables with sequential names; as you've just discovered, now you have a problem in addressing them.
See the FAQ that talks about how to avoid the problem; we don't know how these were created so the best way to choose isn't clear.

类别

在 Help Center 和 File Exchange 中查找有关 Annotations 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by