Not able to install techchart

[kapilravi]

While installing the package I get the following error

cpttrend.cpp:142:27: error: use of undeclared identifier 'PI'
ret = double(n)/2log(2PI) + double(n)/2*log(variance) + double(n)/2;
^
1 error generated.
make: *** [cpttrend.o] Error 1
ERROR: compilation failed for package ‘techchart’

Kindly help