function?SPI?=?CalculateSPI（?Data?）
%SPI?Summary?of?this?function?goes?here
%???Detailed?explanation?goes?here
%?????c0=2.515517;
%?????c1=0.802853;
%?????c2=0.010328;
%?????d1=1.432788;
%?????d2=0.189269;
%?????d3=0.001308;

????sz?=?size（Data1）;
????
????ZerosCount?=?sum（Data==01）;
????avgP?=?sum（Data1）./（sz-ZerosCount）;

????X_n?=?Data;
????X_n（X_n?==?0）?=?1;
%?????Product?=?prod（X_n?2）;
%??