|
|
Sponsored Content
Top Forums
Programming
Class Pointer initialization C++
Post 302519655 by Corona688 on Wednesday 4th of May 2011 02:35:41 PM
05-04-2011
|
|
10 More Discussions You Might Find Interesting
1. Programming
Hi
We are using a code generator for initializing structures with the #define macro. Compiling it with the GCC 2.8.1 (with -ansi) it OK. But when we are using the SUN C 5.0 compiler it screams.
Following is a code sample:
#include <stdlib.h>
#include <stdio.h>
typedef struct TEST3 {... (4 Replies)
Discussion started by: amatsaka
4 Replies
2. Programming
If one wants to get a start address of a array or a string or a block of memory via a function, there are at least two methods to achieve it:
(1) one is to pass a pointer-to-pointer parameter, like:
int my_malloc(int size, char **pmem)
{
*pmem=(char *)malloc(size);
if(*pmem==NULL)... (11 Replies)
Discussion started by: aaronwong
11 Replies
3. UNIX for Dummies Questions & Answers
im just trying to have some fun and kill some time writing a c++ program that has a person type in a car make and model then gives them a year and a price. or something like that. i always have problems getting it goin but once the ball is rolling im usually pretty good. anyone wanna help me out? ... (1 Reply)
Discussion started by: rickym2626
1 Replies
4. Programming
Hi, i have a question about C++. Is it possible to declare a class with a member ot the same class? For example, a linked list or i want to convert this C code to C++ class (Elemento)
typedef struct elemento
{
char name;
char value;
List<struct elemento> ltElementos;
... (7 Replies)
Discussion started by: pogdorica
7 Replies
5. Programming
I'll be gratefull for any help. Thanks.
:)
This is the non class type error:
# g++ -I/usr/include/mysql -I/usr/include/mysql++ -lmysqlpp -L/usr/lib/mysql -L/usr/local/lib/mysql++ loaddsgsports.cpp -o loaddsgsports
loaddsgsports.cpp: In function âint outputToImport(const char*, const char*,... (1 Reply)
Discussion started by: sepoto
1 Replies
6. Programming
Hi,
I believe the next code is wrong:
class Egg {
Egg e;
int i;
Egg(int ii=0) : i(ii) {}
};
because you would end up with an endless definition (memory allocation) of Egg objects, thus int i.
Ok, so God Eckel proposes for a singleton:
class Egg {
static Egg e;
int... (5 Replies)
Discussion started by: xavipoes
5 Replies
7. UNIX for Advanced & Expert Users
Hi all!
I am trying to register a device in an existing device class, but I am
having trouble getting the pointer to an existing class.
I can create a class in a module, get the pointer to it and then use
it to register the device with:
*cl = class_create(THIS_MODULE, className);... (0 Replies)
Discussion started by: hdaniel@ualg.pt
0 Replies
8. Programming
I have the two class definition as follows.
class A { public: int a; };
class B : virtual public A{ };
The size of class A is shown as 4, and size of class B is shown as 16. Why is this effect ?. (2 Replies)
Discussion started by: techmonk
2 Replies
9. Programming
Hello All,
I am a learner in C++. I was testing my inheritance knowledge with following piece of code.
#include <iostream>
using namespace std;
class base
{
public :
void display()
{
cout << "In base display()" << endl;
}
void display(int k)
{... (2 Replies)
Discussion started by: anand.shah
2 Replies
10. Programming
const int VALUES = {7,4,2,1,0}; //or int VALUES = {7,4,2,1,0};this statement inside a class definition gives error. Why? (3 Replies)
Discussion started by: milhan
3 Replies
LEARN ABOUT OSX
fuzzy
math::fuzzy(n) Tcl Math Library math::fuzzy(n) __________________________________________________________________________________________________________________________________________________ NAME
math::fuzzy - Fuzzy comparison of floating-point numbers SYNOPSIS
package require Tcl ?8.3? package require math::fuzzy ?0.2? ::math::fuzzy::teq value1 value2 ::math::fuzzy::tne value1 value2 ::math::fuzzy::tge value1 value2 ::math::fuzzy::tle value1 value2 ::math::fuzzy::tlt value1 value2 ::math::fuzzy::tgt value1 value2 ::math::fuzzy::tfloor value ::math::fuzzy::tceil value ::math::fuzzy::tround value ::math::fuzzy::troundn value ndigits _________________________________________________________________ DESCRIPTION
The package Fuzzy is meant to solve common problems with floating-point numbers in a systematic way: o Comparing two numbers that are "supposed" to be identical, like 1.0 and 2.1/(1.2+0.9) is not guaranteed to give the intuitive result. o Rounding a number that is halfway two integer numbers can cause strange errors, like int(100.0*2.8) != 28 but 27 The Fuzzy package is meant to help sorting out this type of problems by defining "fuzzy" comparison procedures for floating-point numbers. It does so by allowing for a small margin that is determined automatically - the margin is three times the "epsilon" value, that is three times the smallest number eps such that 1.0 and 1.0+$eps canbe distinguished. In Tcl, which uses double precision floating-point numbers, this is typically 1.1e-16. PROCEDURES
Effectively the package provides the following procedures: ::math::fuzzy::teq value1 value2 Compares two floating-point numbers and returns 1 if their values fall within a small range. Otherwise it returns 0. ::math::fuzzy::tne value1 value2 Returns the negation, that is, if the difference is larger than the margin, it returns 1. ::math::fuzzy::tge value1 value2 Compares two floating-point numbers and returns 1 if their values either fall within a small range or if the first number is larger than the second. Otherwise it returns 0. ::math::fuzzy::tle value1 value2 Returns 1 if the two numbers are equal according to [teq] or if the first is smaller than the second. ::math::fuzzy::tlt value1 value2 Returns the opposite of [tge]. ::math::fuzzy::tgt value1 value2 Returns the opposite of [tle]. ::math::fuzzy::tfloor value Returns the integer number that is lower or equal to the given floating-point number, within a well-defined tolerance. ::math::fuzzy::tceil value Returns the integer number that is greater or equal to the given floating-point number, within a well-defined tolerance. ::math::fuzzy::tround value Rounds the floating-point number off. ::math::fuzzy::troundn value ndigits Rounds the floating-point number off to the specified number of decimals (Pro memorie). Usage: if { [teq $x $y] } { puts "x == y" } if { [tne $x $y] } { puts "x != y" } if { [tge $x $y] } { puts "x >= y" } if { [tgt $x $y] } { puts "x > y" } if { [tlt $x $y] } { puts "x < y" } if { [tle $x $y] } { puts "x <= y" } set fx [tfloor $x] set fc [tceil $x] set rounded [tround $x] set roundn [troundn $x $nodigits] TEST CASES
The problems that can occur with floating-point numbers are illustrated by the test cases in the file "fuzzy.test": o Several test case use the ordinary comparisons, and they fail invariably to produce understandable results o One test case uses [expr] without braces ({ and }). It too fails. The conclusion from this is that any expression should be surrounded by braces, because otherwise very awkward things can happen if you need accuracy. Furthermore, accuracy and understandable results are enhanced by using these "tolerant" or fuzzy comparisons. Note that besides the Tcl-only package, there is also a C-based version. REFERENCES
Original implementation in Fortran by dr. H.D. Knoble (Penn State University). P. E. Hagerty, "More on Fuzzy Floor and Ceiling," APL QUOTE QUAD 8(4):20-24, June 1978. Note that TFLOOR=FL5 took five years of refereed evolution (publication). L. M. Breed, "Definitions for Fuzzy Floor and Ceiling", APL QUOTE QUAD 8(3):16-23, March 1978. D. Knuth, Art of Computer Programming, Vol. 1, Problem 1.2.4-5. BUGS, IDEAS, FEEDBACK This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category math :: fuzzy of the Tcllib SF Trackers [http://sourceforge.net/tracker/?group_id=12883]. Please also report any ideas for enhancements you may have for either package and/or documentation. KEYWORDS
floating-point, math, rounding CATEGORY
Mathematics math 0.2 math::fuzzy(n)