genVectorNegate
in genMath.lib
Vector Functions Function List by Category Alphabetical Function List
int genVectorNegate(
float *VectorA, // pointer to array holding
vector A
float *VectorB, // pointer to array for vector B
int dimen)
// dimension of vectors A and B
This function computes the negative of a vector of dimension n:
b(i) = -a(i)
The explicit routines VectorNegate2d and VectorNegate3d are faster due to code
optimizations in the explicit algorithms.
The
return code is errno, defined in the C standard library (math.h). This is
an integer value
for math errors.
Sample Application:
/////////// splgnVNg.c for genVectorNegate Library Function ////////// // // // // For this sample, 3-d vectors are used. The vector is // // stored in array a and the negative is returned in array b. // // // //////////////////////////////////////////////////////////////////////
//////////////////////////// INCLUDES //////////////////////////////// #include "stdio.h" #include "genMath.h" ////////////////////////////// MAIN ////////////////////////////////// void main() { //local declarations //integers int i; // dimension counter int retcode; // return code for call to genVectorNegate //floats float a[3]; // vector A float b[3]; // vector B //character strings char ch; //input string to exit //intialize the A vectors a[0] = (float)1.234; a[1] = (float)-.678; a[2] = (float)10.3; //negate the vector retcode = genVectorNegate(a,b,3); //display the result printf("%s", "Resultant Components: \n\n"); for(i=0;i<=2;++i){ printf("%s%d%s%f%s", "b[",i,"] = ", b[i],"\n"); } printf("%s","\n"); //display closing message and wait for <enter> before exiting printf("Press <Enter> to end"); scanf("%c", &ch); } // End Main
//////////////////////// End splgnVNg.c ///////////////////////
The reader may verify that the vector (array) a is negated.
Output from the test program splgnVNg.c:
Resultant Components:
b[0] = -1.234000
b[1] = 0.678000
b[3] = -10.300000