Draw a line and a plane at fixed ponit in 2d and 3d plot

Hello I have a 2d plot

where at vertical axis(Y) at a particular point say 0.0039 i want to draw a line parallel to X axis...

and in case of 3d plot I have to draw plane along vertical z axis at same point...

is matlab has any related function to do so....

actually what I want to do is http://s8.postimage.org/nyonm4hs5/fig.jpg in this figure i need to draw a line at 3.9*10-3 horizontally ,how to do this? regards

[Jan]

In 3D you need three coordinates to determine a plane. Does "plane along the Z axis" mean "perpendiculare to Z axis"? You cannot orient a plane along a line in 3D.

Answer 1

[Azzi Abdelmalek]

 x=0.0039
 plot([-10 10],[x x])

[Jan]

"Parallel to X axis", so swap the arguments.

[joy]

Actually my situation is like this....

actually I have prob of occurrence along Y axis...(vertical) and along horizontal ( X axis) i have data ranging from 0 to 255.. I want to have grid only at particular 0.0039 value at Y axis.......

[joy]

Is it possible to draw single grid line at a particular point in vertical axis......

[Azzi Abdelmalek]

Ok Simon

 x=0.0039
 plot([[-10 10],[x x])

I was confused by "vertical axis(Y)"

[Azzi Abdelmalek]

Or use

 y=0.0039
 xlim=get(gca,'xlim')
 plot(xlim,[y y])

Answer 2

[Jan]

How do you want to display the plane? An opaque SURF object will most likely hide all interesting details of the plot. What about a semi-transparent SURF object with an opaque border? Or a disc? Or a bunch of points?

[joy]

I have prob of occurrence on z...a nd my data are along my x and y axis...I want to draw a plane or level at 0.0039 //there might be some point above this prob of occurrence and some shall be below of it..so that I could assume.......