From a88f1ebe22a01c2c40eb42b8d63fae520ea0fa82 Mon Sep 17 00:00:00 2001
From: vtvivian <27768054+vtvivian@users.noreply.github.com>
Date: Mon, 12 Sep 2022 17:31:26 +0100
Subject: [PATCH] Match map plot direction to a vector3d

Useful for when you want to plot or measure something wrt e.g. 'north' or 'west' on the map but don't want to hard code it as vector3d.X or Y, might be useful when looking at the same sample with different EBSD systems.

I'm not sure which folder this function could go into
---
 vector3dnwse.m | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 vector3dnwse.m

diff --git a/vector3dnwse.m b/vector3dnwse.m
new file mode 100644
index 000000000..39b809280
--- /dev/null
+++ b/vector3dnwse.m
@@ -0,0 +1,98 @@
+function vecOut = vector3dnwse(nwseIn)
+% find the vector3d corresponding to a NWSE map plot direction
+% so you can do something like vector3d.x but instead vector3d.north
+% nwseIn should be a character array or number
+
+
+%% 1. find out where in the map (NWSE) points along X,-X,Y,-Y
+%up to one of these is empty
+dirX = getMTEXpref('xAxisDirection');
+dirY = getMTEXpref('yAxisDirection');
+dirZ = getMTEXpref('zAxisDirection');
+
+% UpDown outputs {1 2} {'outOfPlane','intoPlane'};
+% NWSE outputs {1 2 3 4} from {'east','north','west','south'}
+
+if ~isempty(dirZ)
+    vZ = UpDown(dirZ);
+else
+    try
+        % if Z points out, mod(vX,4) is smaller than mod(vY,4)
+        vX = NWSE(dirX);
+        vY = NWSE(dirY);
+        if mod(vX,4) < mod(vY,4)
+            vZ = 1;
+        elseif mod(vX,4) > mod(vY,4) %otherwise Z must point in
+            vZ = 2;
+        end
+    catch
+        %either the coordinates are badly defined or something went wrong
+        error('vector3dnwse: which way is Z pointing?');
+    end
+end
+
+if ~isempty(dirX)
+    vX = NWSE(dirX);
+else
+    try
+        vY = NWSE(dirY);
+        if vZ == 1  % Z points out, so X < Y
+            vX = checkmod(mod(vY-1,4));
+        elseif vZ == 2 %otherwise Z points in so X > Y
+            vX = checkmod(mod(vY+1,4));
+        end
+        if vX==0 %mod(0,4) and mod(4,4) both to zero but we don't want this
+            vX=4;
+        end
+    catch
+        %either the coordinates are badly defined or something went wrong
+        error('vector3dnwse: which way is X pointing?');
+    end
+end
+
+if ~isempty(dirY)
+    vY = NWSE(dirY);
+else
+    try
+        if vZ == 1 % Z points out, so X < Y
+            vY = checkmod(mod(vX+1,4));
+        elseif vZ == 2 %otherwise Z points in so X > Y
+            vY = checkmod(mod(vX-1,4));
+        end
+    catch
+        %either the coordinates are badly defined or something went wrong
+        error('vector3dnwse: which way is Y pointing?');
+    end
+end
+
+vXminus = checkmod(mod(vX+2,4));
+vYminus = checkmod(mod(vY+2,4));
+
+%% 2. output a vector3d(+-XY) according to the input map direction (NWSE)
+vList = [vX; vXminus; vY; vYminus];
+vPos = find(vList==NWSE(nwseIn));
+
+switch vPos
+    case 1
+        vecOut = vector3d.X;
+    case 2
+        vecOut = -vector3d.X;
+    case 3
+        vecOut = vector3d.Y;
+    case 4
+        vecOut = -vector3d.Y;
+end
+
+
+    function [vOut] = checkmod(vIn)
+    %mod(0,4) and mod(4,4) both output zero but we actually want 4
+        if vIn==0
+            vOut=4;
+        else
+            vOut=vIn;
+        end
+    end
+
+end
+
+