How to draw line vertical to Y-axis?

99 ビュー (過去 30 日間)
M G
M G 2011 年 11 月 2 日
コメント済み: Walter Roberson 2021 年 4 月 12 日
Hey Matlab users,
If a = [1 2 3 4 5 6 7]; and b = [1 4 7 10 7 4 1]; and the plot it by : figure,plot(a,b), how can I draw let's say a red line vertical to the value 4 and 7 in the y-axis (parallel to x-axis)? So that i can see the window between 4 and 7.
Thanks so much in advance,
Mehdi

採用された回答

Walter Roberson
Walter Roberson 2011 年 11 月 2 日
The same as for your previous question. The solution for that was
yL = get(gca,'YLim');
line([3 3],yL,'Color','r');
line([5 5],yL,'Color','r');
and if you are wanting to draw vertical lines at 4 and 7, you would just change the code to
yL = get(gca,'YLim');
line([4 4],yL,'Color','r');
line([7 7],yL,'Color','r');
Perhaps what you want is instead horizontal lines? If so then
xL = get(gca,'XLim');
line(xL,[4 4],'Color','r');
line(xL,[7 7],'Color','r');
  7 件のコメント
Walter Roberson
Walter Roberson 2021 年 4 月 12 日
These days, see yline()
If you get the current ylim and use it to draw, and then you zoom or pan, then the code I posted back then will not adjust to draw according to the new limits. However, the newer yline() should do that.

サインインしてコメントする。

その他の回答 (5 件)

Noushin Farnoud
Noushin Farnoud 2011 年 11 月 15 日
If you want to draw a line that spans the entire xlim or ylim of your figure, then I suggest that you use hline or vline functions from: http://www.mathworks.com/matlabcentral/fileexchange/1039-hline-and-vline
You can also plot multiple vertical or horizontal lines at the same time using these functions. For example: hline([5,6,8]) draws 3 horizontal lines at x=5, x=6 and x=8.

Eric Sargent
Eric Sargent 2019 年 10 月 15 日
Starting in R2018b you can simply use xline and yline.
In this case:
yline(4,'r');
yline(7,'r');

Sven
Sven 2011 年 11 月 2 日
Hi Mehdi, try this after plotting:
xlims = get(gca,'XLim');
hold on
plot(xlims, [4 4], '-r')
plot(xlims, [7 7], '-r')
  4 件のコメント
Sven
Sven 2011 年 11 月 2 日
Doh! I voted yours up and now it's above mine... that's a blow to my chances for getting accepted! heheh

サインインしてコメントする。


James
James 2014 年 3 月 28 日
There is an excellent answer over on http://stackoverflow.com/a/8108766/1194420 repeated below for convenience. ---
There exist an undocumented function graph2d.constantline:
plot(-2:5, (-2:5).^2-1)
%# vertical line
hx = graph2d.constantline(0, 'LineStyle',':', 'Color',[.7 .7 .7]);
changedependvar(hx,'x');
%# horizontal line
hy = graph2d.constantline(0, 'Color',[.7 .7 .7]);
changedependvar(hy,'y');

Wayne King
Wayne King 2011 年 11 月 2 日
a = [1 2 3 4 5 6 7];
b = [1 4 7 10 7 4 1];
plot(a,b)
hold on
plot(a,4*ones(length(b)),'r');
plot(a,7*ones(length(b)),'r');
  1 件のコメント
Walter Roberson
Walter Roberson 2011 年 11 月 2 日
A bit murky if "a" does not happen to be in sorted order, especially if the drawingmode is set to xor

サインインしてコメントする。

カテゴリ

Find more on Line Plots in Help Center and File Exchange

タグ

Community Treasure Hunt

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

Start Hunting!

Translated by