How to put information gain formula in matlab?

i'm trying to put the information gain technique formula in matlab but im new in this field so can anyone help me please , I attached the formula pdf file above....thanks in advance

InfoGain(t) = - sum_{i=1}^{m} Pr(c_i) log Pr(c_i)

+ Pr(t) sum{i=1}^{m} Pr(c_i|t) log Pr(c_i|t)

+ Pr(~t) sum{i=1}^{m} Pr(c_i|~t) log Pr(c_i|~t);

here error in 'sum'