# How to make a line of fixed length?

3 views (last 30 days)
Mariam Shahab on 29 Nov 2022
Commented: Star Strider on 29 Nov 2022
Hi all,
I want to make a line that has a fixed length and it has a partciular direction. I would appreciate any suggestions for this. Thanks!
##### 2 CommentsShowHide 1 older comment
Mariam Shahab on 29 Nov 2022
Yes, by making, I meant plotting. As for direction, I mean the orientation of the line (i.e. the slope of the line).

Star Strider on 29 Nov 2022
It is relatively straightforward to write an anonymous function for this —
createLine = @(startpt, slope, len) [startpt(1) startpt(1)+len.*cos(atan(slope)); startpt(2) startpt(2)+len.*sin(atan(slope))];
slope = rand % Scalar
slope = 0.9275
startpoint = rand(1,2) % Two-Element Vector
startpoint = 1×2
0.2799 0.8866
long = 10*rand % Scalar
long = 7.5515
linevec = createLine(startpoint, slope, long)
linevec = 2×2
0.2799 5.8167 0.8866 6.0217
Check = [tan(atan2(diff(linevec(2,:)), diff(linevec(1,:)))) hypot(diff(linevec(2,:)),diff(linevec(1,:)))]
Check = 1×2
0.9275 7.5515
figure
plot(linevec(1,:), linevec(2,:))
grid
title(sprintf('Line from (%.2f, %.2f) to (%.2f, %.2f), slope %.2f, length %.2f', [linevec(:,1); linevec(:,2); slope; long]))
Experiment with the ‘createLine’ function.
.
##### 2 CommentsShowHide 1 older comment
Star Strider on 29 Nov 2022
As always, my pleasure!

Vilém Frynta on 29 Nov 2022
You can specify length with numbers of your choice.
You can specify direction numerically as well, you just need to use your imagination and get creative.
x = [1 11];
y = [2 22];
line(x,y);
Mariam Shahab on 29 Nov 2022

### Categories

Find more on Entering Commands in Help Center and File Exchange

### Community Treasure Hunt

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

Start Hunting!

Translated by