When i tyr this, it gives me a syntax error...i tried removing quotes,removing spaces,replacing -eq with '='.. Can somebody suggest that is the problem?
if ]; then (4 Replies)
Hi,
I am trying to compile a program (not coded by me), and i'm getting this error:
203: error: lvalue required as left operand of assignment
As you may be guessing, the program doesn't compile, the line number 203 is the following:
... (2 Replies)
Hey all. I've been working on some fun with C and decided to write a Rock Paper Scissors game. The problem is, that when I try to compile the file, it gives "lvalue required as left operand of assignment" error. The error line is here:
for ((point1=0 && point2=0); ((point1=3) || (point2=3));... (4 Replies)
Hi,
This code was originally to print a sine function table. I modified it to print a tangent function table. I got an "lvalue" error which I can't solve...Any hint on why am I getting this error?
Here is the code:
// sintab.cpp
// Creates a tangent function table
#include <iostream>... (2 Replies)
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
Create a script that displays output with a specific parameter.
For example, for a script called score... (1 Reply)
1. After trying to compile code error is given Lvalue required as left operand of assignment.
2. Relevant commands, code, scripts, algorithms:
if , else if
3. The attempts at a solution (include all code and scripts):
/*
File: incircles.cpp
Created by: James Selhorst
... (2 Replies)
Does anyone know how this line in bash works?
local gotbase= force= nicelevel corelimit
local pid base= user= nice= bg= pid_file=
local cgroup=
These lines are part of the daemon function inside the "functions" file at /etc/init.d in RH. (3 Replies)
Hi I'm new to shell programming. How do I extract the size of an operand in a simple instruction in a C program? Lets say there is an addition a+b somewhere in a C code where a and b are integers. How to extract the size of a & b in bits? Is there something called intermediate code before an... (4 Replies)
When I create a bootable Linux distro installation USB drive, I use this command: sudo dd if=/Path/to/linux_distro.iso of=/dev/rdisk<disk number>
bs=<number of bytes>
When I look it up, I've seen variations of people choosing 4M, and I think 8M, 2M, and maybe even 1M.
If I leave the operand... (4 Replies)
Discussion started by: Quenz
4 Replies
LEARN ABOUT BSD
atan2
SIN(3M)SIN(3M)NAME
sin, cos, tan, asin, acos, atan, atan2 - trigonometric functions and their inverses
SYNOPSIS
#include <math.h>
double sin(x)
double x;
double cos(x)
double x;
double tan(x)
double x;
double asin(x)
double x;
double acos(x)
double x;
double atan(x)
double x;
double atan2(y,x)
double y,x;
DESCRIPTION
Sin, cos and tan return trigonometric functions of radian arguments x.
Asin returns the arc sine in the range -pi/2 to pi/2.
Acos returns the arc cosine in the range 0 to
Atan returns the arc tangent in the range -pi/2 to pi/2.
On a VAX,
atan2(y,x) := atan(y/x) if x > 0,
sign(y)*(pi - atan(|y/x|)) if x < 0,
0 if x = y = 0, or
sign(y)*pi/2 if x = 0 != y.
DIAGNOSTICS
On a VAX, if |x| > 1 then asin(x) and acos(x) will return reserved operands and errno will be set to EDOM.
NOTES
Atan2 defines atan2(0,0) = 0 on a VAX despite that previously atan2(0,0) may have generated an error message. The reasons for assigning a
value to atan2(0,0) are these:(1) Programs that test arguments to avoid computing atan2(0,0) must be indifferent to its value. Programs that require it to be invalid
are vulnerable to diverse reactions to that invalidity on diverse computer systems.(2) Atan2 is used mostly to convert from rectangular (x,y) to polar (r,theta) coordinates that must satisfy x = r*cos theta and y = r*sin
theta. These equations are satisfied when (x=0,y=0) is mapped to (r=0,theta=0) on a VAX. In general, conversions to polar coordinates
should be computed thus:
r := hypot(x,y); ... := sqrt(x*x+y*y)
theta := atan2(y,x).
(3) The foregoing formulas need not be altered to cope in a reasonable way with signed zeros and infinities on a machine that conforms to
IEEE 754; the versions of hypot and atan2 provided for such a machine are designed to handle all cases. That is why atan2(+-0,-0) =
+-pi, for instance. In general the formulas above are equivalent to these:
r := sqrt(x*x+y*y); if r = 0 then x := copysign(1,x);
if x > 0 then theta := 2*atan(y/(r+x))
else theta := 2*atan((r-x)/y);
except if r is infinite then atan2 will yield an appropriate multiple of pi/4 that would otherwise have to be obtained by taking limits.
ERROR (due to Roundoff etc.)
Let P stand for the number stored in the computer in place of pi = 3.14159 26535 89793 23846 26433 ... . Let "trig" stand for one of
"sin", "cos" or "tan". Then the expression "trig(x)" in a program actually produces an approximation to trig(x*pi/P), and "atrig(x)"
approximates (P/pi)*atrig(x). The approximations are close, within 0.9 ulps for sin, cos and atan, within 2.2 ulps for tan, asin, acos
and atan2 on a VAX. Moreover, P = pi in the codes that run on a VAX.
In the codes that run on other machines, P differs from pi by a fraction of an ulp; the difference matters only if the argument x is huge,
and even then the difference is likely to be swamped by the uncertainty in x. Besides, every trigonometric identity that does not involve
pi explicitly is satisfied equally well regardless of whether P = pi. For instance, sin(x)**2+cos(x)**2 = 1 and sin(2x) = 2sin(x)cos(x) to
within a few ulps no matter how big x may be. Therefore the difference between P and pi is most unlikely to affect scientific and engi-
neering computations.
SEE ALSO math(3M), hypot(3M), sqrt(3M), infnan(3M)AUTHOR
Robert P. Corbett, W. Kahan, Stuart I. McDonald, Peter Tang and, for the codes for IEEE 754, Dr. Kwok-Choi Ng.
4th Berkeley Distribution May 12, 1986 SIN(3M)