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Enhance the logest.c utility with new operators: "dup", "inv", "log", and

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"nlogn".  Provide help on an invalid input.

FossilOrigin-Name: b4bd2a062c4baf5f622d61b7411f00de5904ef56
This commit is contained in:
drh
2014-03-27 14:05:38 +00:00
parent 68916c9fd3
commit 382bdeabef
3 changed files with 52 additions and 26 deletions
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62
tool/logest.c
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@@ -17,13 +17,7 @@
**
** ./LogEst ARGS
**
** Arguments:
**
** 'x' Multiple the top two elements of the stack
** '+' Add the top two elements of the stack
** NUM Convert NUM from integer to LogEst and push onto the stack
** ^NUM Interpret NUM as a LogEst and push onto stack.
**
** See the showHelp() routine for a description of valid arguments.
** Examples:
**
** To convert 123 from LogEst to integer:
@@ -97,12 +91,31 @@ static LogEst logEstFromDouble(double x){
return e*10;
}
int isInteger(const char *z){
while( z[0]>='0' && z[0]<='9' ) z++;
return z[0]==0;
}
int isFloat(const char *z){
while( z[0] ){
if( z[0]=='.' || z[0]=='E' || z[0]=='e' ) return 1;
z++;
}
return 0;
char c;
while( ((c=z[0])>='0' && c<='9') || c=='.' || c=='E' || c=='e'
|| c=='+' || c=='-' ) z++;
return z[0]==0;
}
static void showHelp(const char *zArgv0){
printf("Usage: %s ARGS...\n", zArgv0);
printf("Arguments:\n"
" NUM Convert NUM from integer to LogEst and push onto the stack\n"
" ^NUM Interpret NUM as a LogEst and push onto stack\n"
" x Multiple the top two elements of the stack\n"
" + Add the top two elements of the stack\n"
" dup Dupliate the top element on the stack\n"
" inv Take the reciprocal of the top of stack. N = 1/N.\n"
" log Find the LogEst of the number on top of stack\n"
" nlogn Compute NlogN where N is the top of stack\n"
);
exit(1);
}
int main(int argc, char **argv){
@@ -111,30 +124,43 @@ int main(int argc, char **argv){
LogEst a[100];
for(i=1; i<argc; i++){
const char *z = argv[i];
if( z[0]=='+' ){
if( strcmp(z,"+")==0 ){
if( n>=2 ){
a[n-2] = logEstAdd(a[n-2],a[n-1]);
n--;
}
}else if( z[0]=='x' ){
}else if( strcmp(z,"x")==0 ){
if( n>=2 ){
a[n-2] = logEstMultiply(a[n-2],a[n-1]);
n--;
}
}else if( strcmp(z,"dup")==0 ){
if( n>0 ){
a[n] = a[n-1];
n++;
}
}else if( strcmp(z,"log")==0 ){
if( n>0 ) a[n-1] = logEstFromInteger(a[n-1]) - 33;
}else if( strcmp(z,"nlogn")==0 ){
if( n>0 ) a[n-1] += logEstFromInteger(a[n-1]) - 33;
}else if( strcmp(z,"inv")==0 ){
if( n>0 ) a[n-1] = -a[n-1];
}else if( z[0]=='^' ){
a[n++] = atoi(z+1);
}else if( isFloat(z) ){
}else if( isInteger(z) ){
a[n++] = logEstFromInteger(atoi(z));
}else if( isFloat(z) && z[0]!='-' ){
a[n++] = logEstFromDouble(atof(z));
}else{
a[n++] = logEstFromInteger(atoi(z));
showHelp(argv[0]);
}
}
for(i=n-1; i>=0; i--){
if( a[i]<0 ){
printf("%d (%f)\n", a[i], 1.0/(double)logEstToInt(-a[i]));
printf("%5d (%f)\n", a[i], 1.0/(double)logEstToInt(-a[i]));
}else{
sqlite3_uint64 x = logEstToInt(a[i]+100)*100/1024;
printf("%d (%lld.%02lld)\n", a[i], x/100, x%100);
printf("%5d (%lld.%02lld)\n", a[i], x/100, x%100);
}
}
return 0;