@sym/prevprime: added prevprime (fixes #722)

Added input check and some error tests
gnu-octave · Jan 15, 2017 · 853450c · 853450c
1 parent a2ad71a
commit 853450c
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/inst/@sym/prevprime.m b/inst/@sym/prevprime.m
@@ -38,6 +38,8 @@
 
 function y = prevprime(x)
 
+  if (nargin ~= 1) print_usage () end
+
   %y = elementwise_op ('prevprime', x);
 
   % workaround as upstream SymPy returns int, not sym
@@ -50,6 +52,9 @@
 %!assert (isequal (prevprime(sym(20)), 19));
 %!assert (isequal (prevprime(sym([3 5 10])), [2 3 7]));
 
+%!error(prevprime(sym(2)))
+%!error(prevprime(sym(-2)))
+
 %!test
 %! % result is a sym
 %! p = prevprime(sym(3));