Correct typo in help

Author: andymilne

spShift.m

@@ -9,7 +9,7 @@
 %   When 'shifts' is a row vector, all entries of the array are shifted by the
 %   amounts specified in 'shifts': the nth entry of 'shifts' is the shift for
 %   the nth dimension of the N-dimensional array. When 'shifts' is a matrix,
-%   its mth row gives the N-diensional shift for the mth nonzero element of the
+%   its mth row gives the N-dimensional shift for the mth nonzero element of the
 %   full array (i.e., the mth entry of sparse array structure's 'Ind' and 'Val'
 %   fields).
 %
@@ -103,4 +103,4 @@
     spC = spSum(spC,nDimA);
 else
 
-end
+end