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Homework and Emergencies Homework & Coursework Questions Compiler error "lvalue required as left operand of assignment" Post 302700935 by Corona688 on Friday 14th of September 2012 12:08:26 PM
Old 09-14-2012
Just to make the error plain:

Code:
else if ((sqrt((dx2*dx2)+(dy2*dy2))>=b),(sqrt((dx3*dx3)=(dy3*dy3))>=c),(sqrt((dx1*dx1)+(dy1*dy1))<=a))

I should point out, though, that == doesn't work very well with floating point either. It will be extremely picky. Is 3.000001 equal to 3.000002? No. Only 3.0000001000 will be exactly the same as 3.0000001000. There's also the problem that the same number can appear in several different ways in floating point.

So don't check if floats are equal. Check if they're "close enough" by subtracting them, taking the absolute value, and seeing if the result is less than the maximum distance apart you want:

Code:
#include <math.h>

bool isequal(double a, double b, double accuracy)
{
        return(fabs(a-b)<=accuracy);
}

int main(void)
{
        double a=9.00001, b=9.00002;
        cout << "Equal to 0.00000001 precision? " << isequal(a, b,   0.00000001) <<endl;
        cout << "Equal to 0.0001 precision? " << isequal(a, b,   0.0001) << endl;
}

 

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DROP 
OPERATOR(7) SQL Commands DROP OPERATOR(7) NAME
DROP OPERATOR - remove an operator SYNOPSIS
DROP OPERATOR [ IF EXISTS ] name ( { lefttype | NONE } , { righttype | NONE } ) [ CASCADE | RESTRICT ] DESCRIPTION
DROP OPERATOR drops an existing operator from the database system. To execute this command you must be the owner of the operator. PARAMETERS
IF EXISTS Do not throw an error if the operator does not exist. A notice is issued in this case. name The name (optionally schema-qualified) of an existing operator. lefttype The data type of the operator's left operand; write NONE if the operator has no left operand. righttype The data type of the operator's right operand; write NONE if the operator has no right operand. CASCADE Automatically drop objects that depend on the operator. RESTRICT Refuse to drop the operator if any objects depend on it. This is the default. EXAMPLES
Remove the power operator a^b for type integer: DROP OPERATOR ^ (integer, integer); Remove the left unary bitwise complement operator ~b for type bit: DROP OPERATOR ~ (none, bit); Remove the right unary factorial operator x! for type bigint: DROP OPERATOR ! (bigint, none); COMPATIBILITY
There is no DROP OPERATOR statement in the SQL standard. SEE ALSO
CREATE OPERATOR [create_operator(7)], ALTER OPERATOR [alter_operator(7)] SQL - Language Statements 2010-05-14 DROP OPERATOR(7)
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