Tagged Questions

For questions about calculating intersections using {tikz-pgf} or {pgfplots}, including PGF's `intersections` library.

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10
votes
2answers
1k views

Intersection of 2 surface plots in pgfplots

My question is pretty much a duplicate of this one. I'd like pgfplots to display the intersection between tho surface plots properly. Unfortunately, my function is quite different from the one in the ...
4
votes
1answer
81 views

Why two macros in intersections are not expancded?

Two path names inside intersections are not working. Only one macro seems to work. I have tries all the combinations of macro expansion but in vain. In the following 'h\x and \vy' is not working. It ...
3
votes
2answers
560 views

Make line extend beyond endpoint and intersect with line

Is it possible to have a line go through two coordinates and then extend until it intersects with another line? The line in question is not horizontal nor vertical (otherwise I could use the ...
1
vote
0answers
37 views

Extract x and y coordinates when using intersectionlibary [duplicate]

Possible Duplicate: Coordinates of intersections I have the following minimal plot \documentclass{standalone} \usepackage{pgfplots} \usetikzlibrary{intersections} ...
9
votes
2answers
481 views

Tikz — Rotating a line around an intersection

I've been trying to rotate a line around an intersection. The problem (I think) is that the intersection is in a previous scope (I need that to have the correct clipping), and the new scope doesn't ...
6
votes
1answer
304 views

TikZ Intersection missing the true intersection slightly

I'm having issues with the intersection feature. It works, but it seems to "miss" the true intersection a bit. The code below produces the error for me. See this image (can't post it directly because ...
3
votes
1answer
279 views

Lines generated with TikZ intersections are too short

My script calculates several intersections of lines (green) with a vertical "wall" (not shown). The intersections (small red dots) are fine. But the lines from one intersection to another intersection ...
17
votes
1answer
1k views

Intersection of two surfaces

I'm trying to create a signed distance function S(x), where I want to intersect S(x) = 0 with a plane. The problem is not to get the two functions into a plot, but to get the two functions to visual ...
8
votes
3answers
654 views

Intersection of lines to draw a convex function

I'm trying to draw (in TikZ) a convex function f constructed as the minimum of the linear functions f1, f2, f3 and f4. To do that, my inclination is to use the intersections of said lines to find the ...
7
votes
1answer
473 views

tikz intersection fails in combination with the library calc

In the second example I am trying to work the the library intersection. It works fine as long as I don't use the calc library. The first example shows my intention. I am using ($2*(w1')$) which ...
10
votes
2answers
1k views

“pgf Error: No shape named i-0 is known”, but only upon 2nd run

Update 2012-01-31: This seems to be a version (and/or OS specific) problem. It breaks on my latest TeXLive2011 on a Mac, but I can get it to run on my PC version of MiKTeX 2.8, and @MarcvanDongen ...
7
votes
3answers
2k views

How to Intersect an arc with a line without calculating the angle

I'd like to draw an optics-related figure, for which I need to draw several beams with varying opening angles, which will need to be labeled. What I've come up at the moment (boiled down to a minimal ...
11
votes
2answers
2k views

Coordinates of intersections

In axis environment I have a curve and a line intersecting it. How can I get components of intersection-1, intersection-2 etc. in axis units? \documentclass{minimal} \usepackage{pgfplots} ...
2
votes
1answer
171 views

finding points on path with given x-coordinate (marking f(x) points for given x's)

A y=f(x) function is given as path; for a set of x-coordinates, I want to place node (x,f(x)) onto the path, and connect it with (x,0) with vertical line. I have not got very far myself: \tikz{ ...
12
votes
3answers
6k views

TikZ: Intersection of two lines

what is the easiest way to determine the intersection of two lines? I tried \usetikzlibrary{intersections} \begin{tikzpicture}[every node/.style={black,above right}] \draw[name path=line 1] (0,0) -- ...
4
votes
1answer
310 views

More: Generalised: Accessing the logic values of a TikZ coordinate

This is a follow-up question to: Generalised: Accessing the logic values of a TikZ coordinate. In that question a PGFplot answer was suggested by jake. I took that answer and modified it to the ...
5
votes
1answer
1k views

How do I name a plot in tikz and use it for intersections?

I want to create a figure with 3 plots, a vertical reference line, and marks at the intersections of each plot with the reference line. The plots come from an external table. Plotting works, but ...
8
votes
1answer
2k views

How to access \xmin, \xmax, \ymin, \ymax from within PGFplots axis environment

In the MWE example below I have the values specified twice, but would prefer not to have to do that. Furthermore, it is possible to allow PGFplots to automatically select these end points so I would ...
11
votes
2answers
3k views

Insertion of perpendicular symbol at intersection of two perpendicular lines

This provides good details on How to draw a line passing through a point and perpendicular to another?. What I would like to do is to extend this somehow to add the usual geometry symbol to indicate ...
4
votes
1answer
564 views

How to specify a name path for the axis in PGFplots

When I use the {axis} environment, the axis are drawn automatically so I am not able to specify a name for them? I would like to be able to compute intersections with the axis as in Intersections in ...
7
votes
1answer
463 views

Is there a way to clear paths previously defined with name path global in TikZ

In the solution to Intersections in PGFplots it was pointed out that each \addplot command was drawn in its own scope and using name path would not survive outside of that \addplot command. The ...
12
votes
1answer
1k views

Intersections in PGFplots

I can get intersections to work in TikZ, but not PGF plots. I defined a command to show the intersections to make sure that it is identical in both cases. Commenting out the \ShowIntersection line in ...
4
votes
0answers
835 views

Drawing tri-axial ellipsoid and intersecting it with a sphere [closed]

I would like to draw a tri-axial ellipsoid (that is, an ellipsoid with three different main axes). I'd also like to draw a sphere in the same picture, showing the curves of intersection between the ...
7
votes
3answers
675 views

Bad intersection of lines in TikZ

Consider the following: \documentclass{minimal} \usepackage{tikz} \begin{document} \begin{tikzpicture}[line width = 4] \coordinate (a) at (0,0); \coordinate (b) at (1,0); \coordinate (c) at (1,1); ...