added trafo c code

diff --git a/vasp_tools/tXp.c b/vasp_tools/tXp.c
new file mode 100644 (file)
index 0000000..54fe5e2
--- /dev/null
+++ b/vasp_tools/tXp.c
@@ -0,0 +1,214 @@
+/*
+ * tXp.c
+ *
+ * author: frank.zirkelbach@physik.uni-augsburg.de
+ *
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+#include <math.h>
+
+int get_line(int fd,char *line,int max) {
+
+        int count,ret;
+
+        count=0;
+
+        while(1) {
+                if(count==max) return count;
+                ret=read(fd,line+count,1);
+                if(ret<=0) return ret;
+                if(line[count]=='\n') {
+                        memset(line+count,0,max-count-1);
+                        //line[count]='\0';
+                        return count+1;
+                }
+                count+=1;
+        }
+}
+
+
+int main(int argc,char **argv) {
+
+       double x1,x2,x3,y1,y2,y3,z1,z2,z3;
+       double x_1,x_2,x_3,y_1,y_2,y_3,z_1,z_2,z_3;
+       double X1,X2,X3,Y1,Y2,Y3,Z1,Z2,Z3;
+       double theta;
+       double costheta,sintheta;
+       double normx,normy,normz;
+       int posr,poso;
+       char file[128],buf[256];
+       char *wptr;
+       char t1,t2,t3;
+       int cnt;
+
+       posr=open("POSCAR",O_RDONLY);
+       if(posr<0) {
+               perror("open POSCAR (read) file\n");
+               return posr;
+       }
+
+       theta=(atof(argv[1])/180.0*M_PI);
+       costheta=cos(theta);
+       sintheta=sin(theta);
+
+       snprintf(file,127,"POSCAR.X%f",theta);
+       poso=open(file,O_WRONLY|O_CREAT);
+       if(poso<0) {
+               perror("open POSCAR (write) file\n");
+               return poso;
+       }
+       
+       // first line
+       cnt=get_line(posr,buf,256);
+       buf[cnt-1]='\n';
+       write(poso,buf,cnt);
+
+       // second line
+       cnt=get_line(posr,buf,256);
+       buf[cnt-1]='\n';
+       write(poso,buf,cnt);
+
+       // basis
+       cnt=get_line(posr,buf,256);
+       wptr=strtok(buf," ");
+       x1=atof(wptr);
+       wptr=strtok(NULL," ");
+       x2=atof(wptr);
+       wptr=strtok(NULL," ");
+       x3=atof(wptr);
+
+       cnt=get_line(posr,buf,256);
+       wptr=strtok(buf," ");
+       y1=atof(wptr);
+       wptr=strtok(NULL," ");
+       y2=atof(wptr);
+       wptr=strtok(NULL," ");
+       y3=atof(wptr);
+
+       cnt=get_line(posr,buf,256);
+       wptr=strtok(buf," ");
+       z1=atof(wptr);
+       wptr=strtok(NULL," ");
+       z2=atof(wptr);
+       wptr=strtok(NULL," ");
+       z3=atof(wptr);
+
+       /* norm */
+       normx=sqrt(x1*x1+x2*x2+x3*x3);
+       normy=sqrt(y1*y1+y2*y2+y3*y3);
+       normz=sqrt(z1*z1+z2*z2+z3*z3);
+
+       /* basis in given basis */
+       X1=(x1*x1+x2*x2+x3*x3)/normx;
+       X2=(y1*x1+y2*x2+y3*x3)/normy;
+       X3=(z1*x1+z2*x2+z3*x3)/normz;
+
+       Y1=(x1*y1+x2*y2+x3*y3)/normx;
+       Y2=(y1*y1+y2*y2+y3*y3)/normy;
+       Y3=(z1*y1+z2*y2+z3*y3)/normz;
+
+       Z1=(x1*z1+x2*z2+x3*z3)/normx;
+       Z2=(y1*z1+y2*z2+y3*z3)/normy;
+       Z3=(z1*z1+z2*z2+z3*z3)/normz;
+
+       printf("Basis expressed by itself:\n");
+       printf("     %f     %f     %f\n",X1,Y1,Z1);
+       printf(" x = %f y = %f z = %f\n",X2,Y2,Z2);
+       printf("     %f     %f     %f\n",X3,Y3,Z3);
+
+       /* transformed basis */
+       x_1=X1;
+       x_2=costheta*X2-sintheta*X3;
+       x_3=sintheta*X2+costheta*X3;
+
+       y_1=Y1;
+       y_2=costheta*Y2-sintheta*Y3;
+       y_3=sintheta*Y2+costheta*Y3;
+
+       z_1=Z1;
+       z_2=costheta*Z2-sintheta*Z3;
+       z_3=sintheta*Z2+costheta*Z3;
+
+       printf("Transformed basis in the given basis:\n");
+       printf("     %f     %f     %f\n",x_1,y_1,z_1);
+       printf(" x = %f y = %f z = %f\n",x_2,y_2,z_2);
+       printf("     %f     %f     %f\n",x_3,y_3,z_3);
+
+       /* transformed basis in cartesian coordinates */
+       X1=(x1/normx*x_1+y1/normy*x_2+z1/normz*x_3);
+       X2=(x2/normx*x_1+y2/normy*x_2+z2/normz*x_3);
+       X3=(x3/normx*x_1+y3/normy*x_2+z3/normz*x_3);
+
+       Y1=(x1/normx*y_1+y1/normy*y_2+z1/normz*y_3);
+       Y2=(x2/normx*y_1+y2/normy*y_2+z2/normz*y_3);
+       Y3=(x3/normx*y_1+y3/normy*y_2+z3/normz*y_3);
+
+       Z1=(x1/normx*z_1+y1/normy*z_2+z1/normz*z_3);
+       Z2=(x2/normx*z_1+y2/normy*z_2+z2/normz*z_3);
+       Z3=(x3/normx*z_1+y3/normy*z_2+z3/normz*z_3);
+
+       printf("Transformed basis in cartesian coordinates:\n");
+       printf("     %f     %f     %f\n",X1,Y1,Z1);
+       printf(" x = %f y = %f z = %f\n",X2,Y2,Z2);
+       printf("     %f     %f     %f\n",X3,Y3,Z3);
+
+       dprintf(poso," %f %f %f\n",X1,X2,X3);
+       dprintf(poso," %f %f %f\n",Y1,Y2,Y3);
+       dprintf(poso," %f %f %f\n",Z1,Z2,Z3);
+
+       // 6th line
+       cnt=get_line(posr,buf,256);
+       buf[cnt-1]='\n';
+       write(poso,buf,cnt);
+
+       // 7th line
+       cnt=get_line(posr,buf,256);
+       buf[cnt-1]='\n';
+       write(poso,buf,cnt);
+
+       // 8th line
+       cnt=get_line(posr,buf,256);
+       buf[cnt-1]='\n';
+       write(poso,buf,cnt);
+
+       while(1) {
+               cnt=get_line(posr,buf,256);
+               if(cnt<=0)
+                       break;
+               wptr=strtok(buf," ");
+               x1=atof(wptr);
+               wptr=strtok(NULL," ");
+               x2=atof(wptr);
+               wptr=strtok(NULL," ");
+               x3=atof(wptr);
+
+               wptr=strtok(NULL," ");
+               t1=wptr[0];
+               wptr=strtok(NULL," ");
+               t2=wptr[0];
+               wptr=strtok(NULL," ");
+               t3=wptr[0];
+
+               X1=x1;
+               X2=costheta*x2+sintheta*x3;
+               X3=costheta*x3-sintheta*x2;
+
+               dprintf(poso," %f %f %f %c %c %c\n",X1,X2,X3,t1,t2,t3);
+       }
+
+       close(posr);
+       close(poso);
+
+       printf("done!\n");
+
+       return 0;
+}
+