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Implement x^y in calculator

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Change-Id: I868b703131675876bd91198b8a53a921152aecba
This commit is contained in:
Moshe Piekarski 2021-05-12 23:11:54 -04:00 • committed by Aidan MacDonald
parent a3f2b64a46
commit 9ccae0421a
1 changed files with 173 additions and 3 deletions
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176
apps/plugins/calculator.c
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@ -720,6 +720,8 @@ static void doMultiple(double* operandOne, int* powerOne,
double operandTwo, int powerTwo);
static void doAdd (double* operandOne, int* powerOne,
double operandTwo, int powerTwo);
static void doExponent(double* operandOne, int* powerOne,
double operandTwo, int powerTwo);
static void printResult(void);
static void formatResult(void);
static void oneOperand(void);
@ -727,6 +729,75 @@ static void oneOperand(void);
static void drawLines(void);
static void drawButtons(int group);
double strtod(const char *nptr, char **endptr);
long long atoll(const char *nptr);
/* -----------------------------------------------------------------------
Standard library function
----------------------------------------------------------------------- */
double strtod(const char *nptr, char **endptr)
{
double out;
long mantissa;
int length=0, end=0;
mantissa=atoll(nptr);
while(!end)
{
switch(*nptr)
{
case '\0':
end=1;
break;
case ',':
case '.':
case '\'':
end=1;
default:
nptr++;
}
}
out=atoll(nptr);
while( (*nptr == '0')||(*nptr == '1')||(*nptr == '2')||(*nptr == '3')||(*nptr == '4')||
(*nptr == '5')||(*nptr == '6')||(*nptr == '7')||(*nptr == '8')||(*nptr == '9') )
{
nptr++;
length++;
}
for(;length;length--)
out /= 10;
out += mantissa;
if(endptr != NULL)
*endptr=(char *) nptr;
return out;
}
// WARNING Unsafe: Use strtoll instead
long long atoll(const char *nptr)
{
long long result=0;
char negative=0;
while( (*nptr == ' ') || (*nptr == '\f') || (*nptr == '\n')||
(*nptr == '\r') || (*nptr == '\t') || (*nptr == '\v') )
nptr++;
if(*nptr == '+')
nptr++;
if(*nptr == '-')
{
negative++;
nptr++;
}
while (*nptr)
{
if( (*nptr < '0') || (*nptr > '9') )
break;
result *=10;
result+= (*(nptr++) -'0');
}
if(negative)
result = 0 - result;
return result;
}
/* -----------------------------------------------------------------------
Handy functions
----------------------------------------------------------------------- */
@ -1048,6 +1119,91 @@ static void doMultiple(double* operandOne, int* powerOne,
(*powerOne) += powerTwo;
}
/* -----------------------------------------------------------------------
exponentiate in scientific number format
----------------------------------------------------------------------- */
static void doExponent(double* operandOne, int* powerOne,
double operandTwo, int powerTwo)
{
char negative=0;
char *lastDigit;
char negativeBuffer[25];
if (*operandOne == 0)
{
if (operandTwo == 0)
{
calStatus=cal_error; // result is undefined
}
else{
*powerOne = 0;
*operandOne = 0;
}
return;
}
if (operandTwo == 0)
{
*powerOne = 1;
*operandOne = 0.1;
return;
}
if (operandTwo < 0)
{
negative+=2;
operandTwo= ABS(operandTwo);
}
if (*operandOne < 0)
{
#if MEMORYSIZE < 8
calStatus=cal_error;
return;
#else
if(powerTwo < 0)
{
calStatus=cal_error; // result is imaginary
return;
}
/*Truncate operandTwo to three places past the radix
in order to eliminate floating point artifacts
(function should set error if truncating a non-integer) */
rb->snprintf(negativeBuffer, 25, "%.*f", powerTwo+3, operandTwo);
operandTwo = strtod(negativeBuffer, NULL);
/*Truncate operandTwo to powerTwo digits by way of string
in order to confirm operandTwo *10^powerTwo is an integer*/
rb->snprintf(negativeBuffer, 25, "%.*f", powerTwo, operandTwo);
if(strtod(negativeBuffer, &lastDigit) != operandTwo)
{
calStatus=cal_error; // result is imaginary
return;
}
if(rb->atoi(lastDigit-1) % 2)
negative++;
#endif
}
(*operandOne) = myLn(ABS(*operandOne)) + (double) (*powerOne) * 2.302585092994046;
(*powerOne) = 0;
doMultiple(operandOne, powerOne, ABS(operandTwo), powerTwo);
while(*powerOne)
{
if(*powerOne > 0)
{
(*operandOne) *= 10;
(*powerOne) --;
}
else{
(*operandOne) /= 10;
(*powerOne) ++;
}
}
(*operandOne) = myExp(*operandOne);
if(negative & 2)
(*operandOne) = 1/(*operandOne);
if(negative & 1)
*operandOne = -(*operandOne);
}
/* -----------------------------------------------------------------------
Handles all one operand calculations
----------------------------------------------------------------------- */
@ -1192,6 +1348,9 @@ static void twoOperands(void)
else
calStatus = cal_error;
break;
case '^':
doExponent(&operand, &operandPower, result, power);
break;
default: /* ' ' */
switchOperands(); /* counter switchOperands() below */
break;
@ -1684,7 +1843,9 @@ static void basicButtonsProcess(void){
#ifdef CALCULATOR_OPERATORS
case_cycle_operators: /* F2 shortkey entrance */
#endif
calStatus = cal_normal;
if (calStatus == cal_typing ||
calStatus == cal_dotted)
calStatus = cal_normal;
formatResult();
operand = result;
operandPower = power;
@ -1740,8 +1901,17 @@ static void sciButtonsProcess(void){
break;
case sci_xy:
/*Not implemented yet
Maybe it could use x^y = exp(y*ln(x))*/
if(!operInputted) {twoOperands(); operInputted = true;}
oper = '^';
#ifdef CALCULATOR_OPERATORS
case_cycle_operators: /* F2 shortkey entrance */
#endif
if (calStatus == cal_typing ||
calStatus == cal_dotted)
calStatus = cal_normal;
formatResult();
operand = result;
operandPower = power;
break;
case sci_sci: