Adding inverse trig functions.

@UncVal/acos.m

@@ -0,0 +1,10 @@
+function obj = acos(x)
+%ACOS acos function for UncVal objects
+obj = x;
+obj.val = acos(x.val);
+m = -1.0./sqrt(1-x.val.^2);
+for k = obj.srcs.keys'
+    obj.srcs(k).sens = m.*obj.srcs(k).sens;
+end
+end
+

@UncVal/acosd.m

@@ -0,0 +1,4 @@
+function obj = acosd(x)
+% acosd arccosine in degrees
+obj = rad2deg(acos(x));
+end

@UncVal/asin.m

@@ -0,0 +1,10 @@
+function obj = asin(x)
+%ASIN asin function for UncVal objects
+obj = x;
+obj.val = asin(x.val);
+m = 1.0./sqrt(1-x.val.^2);
+for k = obj.srcs.keys'
+    obj.srcs(k).sens = m.*obj.srcs(k).sens;
+end
+end
+

@UncVal/asind.m

@@ -0,0 +1,4 @@
+function obj = asind(x)
+% asind arcsine in degrees
+obj = rad2deg(asin(x));
+end

@UncVal/atan.m

@@ -0,0 +1,10 @@
+function obj = atan(x)
+%ATAN arctangent function for UncVal objects
+obj = x;
+obj.val = atan(x.val);
+m = 1.0./(1+x.val.^2);
+for k = obj.srcs.keys'
+    obj.srcs(k).sens = m.*obj.srcs(k).sens;
+end
+end
+

@UncVal/atand.m

@@ -0,0 +1,4 @@
+function obj = atand(x)
+% atand arctangent in degrees
+obj = rad2deg(atan(x));
+end

TEST_UncVal_simple.m

@@ -350,6 +350,48 @@
 assertClose(y.val, 0.0);
 assertClose(var(y), 0.0);
 
+%% Test asin
+x = UncVal(0.3, 0.01, "x");
+y = asin(x);
+z = sin(y);
+assertClose(z.val, x.val);
+assertClose(var(z), var(x));
+
+%% Test asind
+x = UncVal(18, 1, "x");
+y = asind(x);
+z = sind(y);
+assertClose(z.val, x.val);
+assertClose(var(z), var(x));
+
+%% Test acos
+x = UncVal(0.3, 0.01, "x");
+y = acos(x);
+z = cos(y);
+assertClose(z.val, x.val);
+assertClose(var(z), var(x));
+
+%% Test acosd
+x = UncVal(18, 1, "x");
+y = acosd(x);
+z = cosd(y);
+assertClose(z.val, x.val);
+assertClose(var(z), var(x));
+
+%% Test atan
+x = UncVal(0.3, 0.01, "x");
+y = atan(x);
+z = tan(y);
+assertClose(z.val, x.val);
+assertClose(var(z), var(x));
+
+%% Test atand
+x = UncVal(18, 1, "x");
+y = atand(x);
+z = tand(y);
+assertClose(z.val, x.val);
+assertClose(var(z), var(x));
+
 %% Test trig in degrees
 x = UncVal(25.0, 0.1, "x");
 y1 = sind(x);