How can I draw a line with arrow head between 2 data points in a plot

2,142 次查看（过去 30 天）
Amit K
Amit K 2014-10-28
评论： Star Strider 2024-10-22
Hi,
If there are 2 points in XY plane [x1, y1] and [x2, y2] then how can I draw a line with an arrowhead starting from [x1, y1] and ending at [x2, y2]. Basically, I want the plot to look like this:
[x1, y1]--------->[x2, y2]
Preferably, I like the arrow-line to bend (arc) towards the second point.
AK

请先登录，再回答此问题。

采纳的回答

Star Strider
Star Strider 2014-10-29
编辑：MathWorks Support Team 2021-3-17
That’s easy enough with the quiver function:
p1 = [2 3]; % First Point
p2 = [9 8]; % Second Point
dp = p2-p1; % Difference
figure
quiver(p1(1),p1(2),dp(1),dp(2),0)
grid
axis([0 10 0 10])
text(p1(1),p1(2), sprintf('(%.0f,%.0f)',p1))
text(p2(1),p2(2), sprintf('(%.0f,%.0f)',p2))
The final zero in the quiver call turns off the automatic scaling.
The arc would be a bit more challenging, depending on what you intend by arc. I would just use the quiver result.
  8 个评论
显示 6更早的评论
Star Strider
Star Strider 2024-10-22
Ran in:
Another option —
p1 = [2 3]; % First Point
p2 = [9 8]; % Second Point
dp = p2-p1; % Difference
figure
% quiver(p1(1),p1(2),dp(1),dp(2),0)
scatter([p1(1) p2(1)], [p1(2) p2(2)], 125, 'r', 's', 'filled')
grid
axis([0 10 0 10])
text(p1(1),p1(2), sprintf(' (%.0f,%.0f)',p1), 'Horiz','left')
text(p2(1),p2(2), sprintf(' (%.0f,%.0f)',p2), 'Horiz','left')
xapf = @(x,pos,xl) pos(3)*(x-min(xl))/diff(xl)+pos(1); % 'x' Annotation Position Function
yapf = @(y,pos,yl) pos(4)*(y-min(yl))/diff(yl)+pos(2); % 'y' Annotation Position Function
xl = xlim;
yl = ylim;
pos = gca().Position;
annotation('arrow', xapf([p1(1) p2(1)],pos,xl), yapf([p1(2) p2(2)],pos,xl))
The ‘xapf’ and ‘yapf’ anonymous functions make annotation objects easier to work with. (I devised them a few months ago.)
Their entire code requires all these assignments:
xapf = @(x,pos,xl) pos(3)*(x-min(xl))/diff(xl)+pos(1); % 'x' Annotation Position Function
yapf = @(y,pos,yl) pos(4)*(y-min(yl))/diff(yl)+pos(2); % 'y' Annotation Position Function
xl = xlim;
yl = ylim;
pos = gca().Position;
They need all those variables. This example works as documentation for their use.
.

请先登录，再进行评论。

更多回答（4 个）

Sajeer Modavan
Sajeer Modavan 2019-3-14
编辑：Sajeer Modavan 2019-3-14
t = 1:0.1:10; wo = 1;
x = 2*exp(t*wo).*sin(t*wo);
plot(t,x),hold on
plot([6 6],[-1e5 1e5],'--k','Linewidth',1.4)
plot([8.7 8.7],[-1e5 1e5],'--k','Linewidth',1.4)
ylim([-0.3e5 1e4])
% One arrow from left to right with text on left side
x = [0.74 0.79]; % adjust length and location of arrow
y = [0.3 0.3]; % adjust hieght and width of arrow
annotation('textarrow',x,y,'String',' Growth ','FontSize',13,'Linewidth',2)
% Arrow with two head at both end and text between
y = [0.4 0.4];
Xadj = 1.35; % adjust location of left arrow starting point (the sum of this with 'x' should not be negative)
annotation('textarrow',x,y,'String',' Growth ','FontSize',13,'Linewidth',2)
annotation('textarrow',-x+Xadj,y,'String','','FontSize',14,'Linewidth',2)
% One arrow from left to right with text over it
x = [0.56 0.79]; % adjust length and location of arrow
y = [0.5 0.5];
annotation('textarrow',x,y,'FontSize',13,'Linewidth',2)
annotation('textbox',[.6 .3 .7 .27],'EdgeColor','none','String','Growth','FontSize',13,'Linewidth',2)
  1 个评论
Marius Hammer
Marius Hammer 2019-4-26
Could you give an describtion of how the arrow coordinates are set exactly? x and y need to be between 0 and 1 within annotation, so if I want the arrow to go from e.g. (x1,y1) = (3,0.5) and (x2,y2) = (6,0.5) how is x and y adjusted for exact location?

请先登录，再进行评论。

Image Analyst
Image Analyst 2014-10-29
The "Official solution" from the folks at the Mathworks: http://www.mathworks.com/matlabcentral/answers/92988-how-do-i-plot-a-line-that-has-an-arrow-on-the-end-of-it-in-2-d-and-3-d
I use arrow3 from the File Exchange.
Vitaly Fedoseev
Vitaly Fedoseev 2021-5-26
编辑：Vitaly Fedoseev 2024-10-22
Ran in:
The following code (Matlab R2019a) draws an arrow in the plot coordinates from point P1 to point P2 using standard Matlab code. Zoom in/out shifts position of the arrow.
P1=[10, -1]; % from point
P2=[70, 2];
figure;hold on
plot(P1(1), P1(2), 'o')
plot(P2(1), P2(2), 'o')
%xlim([5 80])
%ylim([-5 5]) % must be set before the conversion below
ax=gca;
Pos=ax.Position;
Xlim=xlim;
Ylim=ylim;
X_conv(1)=Pos(1)+Pos(3)/(Xlim(2)-Xlim(1))*(P1(1)-Xlim(1));
X_conv(2)=Pos(1)+Pos(3)/(Xlim(2)-Xlim(1))*(P2(1)-Xlim(1));
Y_conv(1)=Pos(2)+Pos(4)/(Ylim(2)-Ylim(1))*(P1(2)-Ylim(1));
Y_conv(2)=Pos(2)+Pos(4)/(Ylim(2)-Ylim(1))*(P2(2)-Ylim(1));
annotation('arrow', X_conv, Y_conv)
Amit K
Amit K 2014-10-30
编辑：Amit K 2014-10-30
Thank you guys. It worked but not good enough for what I'm doing with the plots. Is it possible to draw an arc instead of a line between the two point going from the starting point to the end point. The two points are not equidistant from the centre. Appreciate for your help.
AK

类别

在 Help Center 和 File Exchange 中查找有关 Vector Fields 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