Add correctness check for trigonometric functions to use_dll test

tests/ramst_normcdf_and_friends.mod

 // Tests the normcdf(), normpdf() and erf() functions, in the static M-file, and in a dynamic C-file
 
-var c k t u v;
-varexo x;
+var c k t u v sin_x cos_x tan_x asin_y acos_y atan_y;
+varexo x y;
 
 parameters alph gam delt bet aa;
 alph=0.5;
@@ -16,10 +16,17 @@ c^(-gam) - (1+bet)^(-1)*(aa*alph*x(+1)*k^(alph-1) + 1 - delt)*c(+1)^(-gam);
 t = normcdf(x, 2, 3);
 u = normpdf(x, 1, 0.5);
 v = erf(x);
+sin_x = sin(x);
+cos_x = cos(x);
+tan_x = tan(x);
+asin_y = asin(y);
+acos_y = acos(y);
+atan_y = atan(y);
 end;
 
 initval;
 x = 1;
+y = 0;
 k = ((delt+bet)/(1.0*aa*alph))^(1/(alph-1));
 c = aa*k^alph-delt*k;
 t = 0;
@@ -35,6 +42,9 @@ shocks;
 var x;
 periods 1;
 values 1.2;
+var y;
+periods 1,2;
+values 0.5, 1;
 end;
 
 simul(periods=20);
@@ -63,3 +73,63 @@ if (abs(oo_.endo_simul(3, 2) - normcdf(1.2, 2, 3)) > 1e-10)
    error('Test failed in dynamic M-file for normcdf')
 end
 
+
+sin_x_pos=strmatch('sin_x',M_.endo_names,'exact');
+if(abs(oo_.steady_state(sin_x_pos) - sin(1)) > 1e-10)
+   error('Test failed in static M-file for sin')
+end
+
+if (abs(oo_.endo_simul(sin_x_pos, 2) - sin(1.2)) > 1e-10)
+   error('Test failed in dynamic M-file for sin')
+end
+
+cos_x_pos=strmatch('cos_x',M_.endo_names,'exact');
+if(abs(oo_.steady_state(cos_x_pos) - cos(1)) > 1e-10)
+   error('Test failed in static M-file for cos')
+end
+
+if (abs(oo_.endo_simul(cos_x_pos, 2) - cos(1.2)) > 1e-10)
+   error('Test failed in dynamic M-file for cos')
+end
+
+tan_x_pos=strmatch('tan_x',M_.endo_names,'exact');
+if(abs(oo_.steady_state(tan_x_pos) - tan(1)) > 1e-10)
+   error('Test failed in static M-file for tan')
+end
+
+if (abs(oo_.endo_simul(tan_x_pos, 2) - tan(1.2)) > 1e-10)
+   error('Test failed in dynamic M-file for tan')
+end
+
+asin_y_pos=strmatch('asin_y',M_.endo_names,'exact');
+if(abs(oo_.steady_state(asin_y_pos) - asin(0)) > 1e-10)
+   error('Test failed in static M-file for asin')
+end
+
+if (abs(oo_.endo_simul(asin_y_pos,1) - asin(0)) > 1e-10) || ...
+        (abs(oo_.endo_simul(asin_y_pos, 2) - asin(0.5)) > 1e-10) || ...
+        (abs(oo_.endo_simul(asin_y_pos, 3) - asin(1)) > 1e-10)
+   error('Test failed in dynamic M-file for asin')
+end
+
+acos_y_pos=strmatch('acos_y',M_.endo_names,'exact');
+if(abs(oo_.steady_state(acos_y_pos) - acos(0)) > 1e-10)
+   error('Test failed in static M-file for acos')
+end
+
+if (abs(oo_.endo_simul(acos_y_pos,1) - acos(0)) > 1e-10) || ...
+        (abs(oo_.endo_simul(acos_y_pos, 2) - acos(0.5)) > 1e-10) || ...
+        (abs(oo_.endo_simul(acos_y_pos, 3) - acos(1)) > 1e-10)
+   error('Test failed in dynamic M-file for acos')
+end
+
+atan_y_pos=strmatch('atan_y',M_.endo_names,'exact');
+if(abs(oo_.steady_state(atan_y_pos) - atan(0)) > 1e-10)
+   error('Test failed in static M-file for atan')
+end
+
+if (abs(oo_.endo_simul(atan_y_pos,1) - atan(0)) > 1e-10) || ...
+        (abs(oo_.endo_simul(atan_y_pos, 2) - atan(0.5)) > 1e-10) || ...
+        (abs(oo_.endo_simul(atan_y_pos, 3) - atan(1)) > 1e-10)
+   error('Test failed in dynamic M-file for atan')
+end
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