/* Does a one-sample t-test of H_0: \mu=c, using IMSL 
   The default value of c is 0, but it can also be specified on the 
     command line */

/* gcc -O2 -o ttest.exe ttest.c -limsl -lfor -lUfor -lm  
 */

#include <stdio.h>	
#include <stdlib.h>	
#include <math.h>	

#define N 10

extern double dtdf_();

int main(int argc, char *argv[])
{
  FILE *fp;
  int i,j;
  double data[N];     
  double mu=0;               /* null hyp. mean -- can be read in; default=0 */
  double mean, sd, t, df;

  sd = mean = 0;
  fp = fopen("sortvec1.dat","r");
  for(i=0;i<N;i++) {  
    fscanf(fp,"%lf", &data[i]);
    mean += data[i];
    sd += data[i]*data[i];
  }
  fclose(fp);

  mean /= N;
  sd = sqrt((sd - mean*mean*N)/(N-1));
  if(argc>1) mu = atof(argv[1]);
  df = N-1.0;
  t = (mean - mu)/(sd/sqrt(N));

  printf("Mean = %g \t Std Dev = %g\n",mean,sd);
  printf("t = %g on %g df\n",t,df);
  t = fabs(t);
  printf("p-value = %g\n\n", 2.0*(1-dtdf_(&t, &df)) );

}

/* in Splus:
sortvec1_scan("sortvec1.dat")
t.test(sortvec1)
*/

/* Fits a linear regression using the IMSL routine DRGIVN */

/* gcc -O2 -o linreg.exe linreg.c -limsl -lfor -lUfor -lm  

   setenv LM_LICENSE_FILE "/usr/pkg/matlab/etc/license.dat"
   gcc -O2 -o linreg.exe linreg.c -L/usr/local/lib/ -lsocket -lnsl -limsl -L/usr/pkg/spro/sun4m_55/lib/ -lF77 -lM77 -lsunmath -lm
 */

#include <stdio.h>	
#include <stdlib.h>	
#include <math.h>	

#define N 30
#define P 5
/* P is the number of independent variables */

int main(int argc, char *argv[])
{
  FILE *fp;
  int i,j;
  double tdata[P+1][N];            /* transpose of data */
  int n=N;                         /* number of cases */
  double bhat[P+1];                /* fitted coefficients */
  double r[P+1][P+1];              /* R from QR of regression */
  double tol=1.0e-8;               /* lots of stuff for IMSL */
  int zero=0,one=1,minusone=-1;
  int ncol=P+1,iind=-P;
  double d[P+1],xmin[P+1],xmax[P+1];
  int irank,nrmiss;		   /* rank of R, # missing obsv */
  double dfe,scpe;		   /* df for SSE, SSE */ 

  fp = fopen("oxide.nh.dat","r");
  for(i=0;i<N;i++) {  
    for(j=0;j<P+1;j++) {             /* note: response is in last column */
      fscanf(fp,"%lf", &tdata[j][i]);  /* read into transpose for IMSL */
    }
  }
  fclose(fp);

  /* fit linear regression */
  drgivn_(&zero,&n,&ncol,tdata,&n,&one,&iind,&one,&minusone,&one,&zero,&zero,&one,&tol,bhat,&ncol,r,&ncol,d,&irank,&dfe,&scpe,&one,&nrmiss,xmin,xmax);

  printf("The regression coefficients are:\n");
  for(i=0;i<P+1;i++) printf(" %8.4f\n",bhat[i]);
  printf("\ns = %g\n\n",sqrt(scpe/dfe));

}

/* in Splus:
oxide_read.table("oxide.nh.dat")
summary(lm(V6~.,data=oxide),cor=F)
*/

/* Computes the eigenvalues of a symmetric matrix using blas/lapack */

/* gcc -O2 -o eigen.exe eigen.c -lapack -lblas -lfor -lUfor -lm
   gcc -O2 -o eigen.exe eigen.c -L/usr/local/lib -lblas -llapack -lg2c -lm
   gcc -O2 -o eigen.exe eigen.c -L/afs/acpub.duke.edu/pkg/spro-4.01/sun4m_5x/SC4.0/lib/ -L/usr/local/lib/ -lsocket -lnsl -llapack -lblas -lF77 -lM77 -lsunmath -lm 
 */

#include <stdio.h>	
#include <stdlib.h>	
#define N 7

extern void dsyev_();

int main(int argc, char *argv[])
{
  int i,j;
  double matrix[N][N];     
  double matcopy[N][N];
  double eigen[N];
  char jobz[2]="N",uplo[2]="U";
  int n=N, lwork=3*N;
  int info;
  double work[3*N];

  for(i=0;i<N;i++) {
    for(j=0;j<=i;j++) {
     matcopy[i][j] = matrix[i][j] = (i+1)*(j+2);
    }
  }

  dsyev_(&jobz,&uplo,&n,matcopy,&n,eigen,work,&lwork,&info);

  printf("For matrix: \n");
  for(i=0;i<N;i++) {
    for(j=0;j<N;j++) printf("%6.3g ",matrix[i][j]);
    printf("\n");
  }
  printf("\nThe eigenvalues are: \n");
  for(i=0;i<N;i++) printf("%g ",eigen[i]);
  printf("\n\n");
  printf("Note that matcopy is now: \n");
  for(i=0;i<N;i++) {
    for(j=0;j<N;j++) printf("%6.3g ",matcopy[i][j]);
    printf("\n");
  }
}

/* In Splus:
mat_matrix(0,ncol=7,nrow=7)
for(i in 1:7) { for(j in 1:i) { mat[i,j]_i*(j+1); mat[j,i]_i*(j+1) }}
eigen(mat,only.values=T)
*/