I would like to convert a float or double variable into unsigned char variable and back.
float number_float = 23.453f;
unsigned char* number_char = (unsigned char*)malloc(sizeof(float));
number_char = reinterpret_cast<unsigned char*> (&number_float);
float* number_float_0 = reinterpret_cast<float*>(&number_char);
I am not getting the same value back.. why?
How can i write a function that will read an "unsigned integer" into a variable of type "unsigned short int"? i can not use cin >> inside the function.. so i am looking for atleast a hint!
View 16 Replies View RelatedI want a code that can convert floating/double value into string/char array(char arr[]) and also it can be run on Boreland C++ 5.02
Here I've a code but it doesn't show all the numbers. Instead, it's showing in exponential form which I don't want!!
int main() {
char* str = new char[30];
float flt = 2.4567F;
sprintf(str, "%.4g", flt );
cout<<str<<endl; //Exponential form even after 6 digits without decimal
return 0;
}
I have two char variables, m_GPSOffset[13] and m_FileName[100]. When m_GPSOffset has a value assigned to it, say for instance +11:25:30. The first entry of the value, in this case +, is always stored in m_FileName. I am clueless on why this is occurring.
View 15 Replies View RelatedHow to change an enum type variable to a string type variable?
View 2 Replies View RelatedI am trying to set a variable of type char equal to an element in an array of characters. For example:
char data[4] = "x+1";
char element;
element = data[2];
This seems like a logical progression from number arrays, but when I print both element and data[2], I get data[2] as expected, but element gives a different character every time (I assume a garbage value).
I'm having a pretty weird problem. I've created an unsigned char array for an image buffer:
buffer_rgb = new unsigned char[_w * _h * 3];
memset(buffer_rgb, 0x0, sizeof(unsigned char)* _w * _h * 3);
And I add pixel color values to it like so:
buffer_rgb[i] = ((unsigned char)(col[0] * 255));
buffer_rgb[i + 1] = ((unsigned char)(col[1] * 255));
buffer_rgb[i + 2] = ((unsigned char)(col[2] * 255));
Where col is a 'vec4' struct with a double[4] with values between 0 and 1 (this is checked and clamped elsewhere, and the output is safely within bounds). This is basically used to store rgb and intensity values.
Now, when I add a constant integer as a pixel value, i.e.:
buffer_rgb[i] = ((unsigned char)255;
Everything works as it should. However, when I use the above code, where col is different for every sample sent to the buffer, the resulting image becomes skewed in a weird way, as if the buffer writing is becoming offset as it goes.
These two images illustrate the problem:
tomsvilans.com/temp/140803_render_skew.png
tomsvilans.com/temp/140803_render_noskew.png
You can see in the 'noskew' image all pixels are the same value, from just using an unchanging int to set them. It seems to work with any value between 0-255 but fails only when this value is pulled from my changing col array.
Whole function is here:
// adds sample to pixel. coordinates must be between (-1,1)
void Frame::addSample(vec4 col, double contrib, double x, double y) {
if (x < -1 || x >= 1 || y < -_aaspect || y >= _aaspect) {
[Code] .....
Can you use data type double or float for an array? ie
double n[];
or
float a;
float m[a];
My code wont accept me changing the data type..will on accept int data type. I get the following error when I try to change the array to double or float..
3310E:C++vector.cpp[Error] invalid types 'double [1000][double]' for array subscript
I came across some code and it's not clear why it is casting an unsigned char * to another pointer type only to free it right after. Here are the relevant structures:
Code:
struct _Edje_Message {
Edje *edje;
Edje_Queue queue;
Edje_Message_Type type;
int id;
unsigned char *msg;
[Code] .....
As you can see, _Edge_Message has a *msg field, but in the function below, they cast it to the other two structure types inside the case blocks of the switch statement only to free it. What is the point or advantage of doing this?
Code:
void
_edje_message_free(Edje_Message *em) {
if (em->msg) {
int i;
switch (em->type) {
[Code] ......
I need to create a stack with the container being an unsigned int. I tried to put in numbers up to four bits each and have the program read the numbers individually. This is the code I am using:
void push(int n)//item n is pushed onto the stack, throw exception on full stack {
string str="Error";
if (isFull())
throw str;
[Code] ....
When I have tested it, the program is reading the numbers as one whole number. For example, I put in the number 2, and it displays the number 2. Then I put in 2 again, but this time it displays the number 10, instead of 2 2.
I just wrote the following simple program:
Code:
#include <stdio.h>
#include <math.h>
int main(void) {
float fx, x;
[Code] ....
The output increases x by 0.1 as expected until x=1.5. After that x becomes 1.600001 and not 1.6 as expected.
I would like to convert a string variable to float.When acquiring data from text file, I use:
while( getline( ifs, temp )) {
numberOfFeatures++;
vecteur.clear();
string::size_type stTemp = temp.find(separateur);
number_descriptorEntries=0;
[code].....
the matrix that I obtain is of type vector<Vec> where Vec is a vector of strings.I want to convert each element of matrixe to a float.
I am writing a math program, using variables of type double, and had initialized all variables to 0.0.
I now realize that not all results will be valid.
Is there a way to explicitly assign a variable of type double a non-numeric value, for example, "NaN", "Undefined", or "Unassigned" or something like that?
That way, when I read through the printout of results, I will realize the "NaN" results indicate a valid solution was not found. Whereas a 0.0 might not stand out.
I'd hate to have to go back and delete the initialization, and then re-assign 998 values just for the sake of 2 non-solutions.
I'm having some trouble with a variable from a database. That variable in that database is of type double.
To read from the database, I'm using a variable dr of type OleDbDataReader.
So far, I've been using dr["variablename"].ToString() to work with the variables from this database - without the ToString part it wasn't working.
However, with this specific variable (I'll call it "var"), I have to do numerical comparisons of >= and <=, so obviously, just using dr["var"].ToString() doesn't work.
Therefore, I tried creating a variable of type double called varConv and setting it as
varConv = Convert.ToDouble(drPen["var"].ToString()).
That doesn't work, gives me an error message saying "Input string was not in a correct format". If I remove the ToString part, it also doesn't work, with a different error message saying "Object cannot be cast from DBNull to other types".
Trying to do a direct comparison, as in dr["var"] >= x also doesn't work, says "Operator '>=' cannot be applied to operands of type 'object' and 'int' ".
Define a constant PI that has a value of 3.14159
- Create a double variable, Radius with an initial value of 10
- Create two double variables. Circum and Area, without initialization
- Using the following formulas, compute circumference and area of the circle:
circumference = pi * r * 2 (here, r means radius)
area = pi * r * r
- Display the result using three variables (numbers must come from variables)
- Expected output: (Don’t forget to display the period at the end of the first line)
Circle with radius of 10.
Circumference = 62.8318 Area = 314.159
Here your supposed to create a program that takes in information and formats it into three columns.
I can't seem to use the float variable unitprice with decimal places here for, if I try to use %.1f and type in an input, the program seems to skip over the second scanf function, not allowing me to put input into the third scanf function as the program runs before I can.
I can use %f on its own and it works but this creates too many zeroes(and you're supposed to set the currency limit to $99999.99).
Code:
#include <stdio.h>
int main(void) {
int itemno, month, year, day;
float unitprice;
[Code]....
So the output should look like three columns. It's just the float that is the issue here....
I'm attempting to pass a couple of variables over to my Item.cpp class, that is description and item_price. However under item.set(description,item_price), i get three errors. One under the . (period) saying : expected an identifier and two more under description and item_price stating that variable " xxx " is not a type name.
Main.cpp
#include <iostream>
#include "item.h"
using namespace std;
using namespace items;
int main(){
int n;
[Code] .....
I have code already and am looking to incorporate something new into it. I am trying to specify a bit size. A snippet of something similar I have is,
Code:
//header.h
int x; Code: //main.cpp
int func1(int a) {
x = a;
}
Is there anyway I can recast the variable x into another type? For example, if func2 had a char parameter instead, can I somehow make x become char type?
I have a bug and when I debugged in some point i needed to know whats inside my char **grid , when i hold mouse over this variable in debug mode i can only see hex or address.. ! i cant see my values grid is 10 * 10 table which hold a number from 1 to 3 .... is there any way for me to see whats inside ?
I'm using visual studio 2013 ultimate ....
I just compiled some code I've been working on at a different OS/compiler and realised that Code: sizeof(unsigned long) returns 4 in one pc and 8 in another.
I've heard that bytesize conventions for basic variables were not particularly "universal" before but this is the 1st time I've had a problem with it.
how do I make a typedef that clearly indicates to whatever compiler compiler I want u32 to be an 32bits unsigned and u64 to be 64bits?
I'm a basic C++ programmer, and I am stuck on this problem. You work for a company that collects a set of numbers. The numbers are located in a data file named "./Data_File". The data file contains two columns. how do you count a certain number on the left column.
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <iomanip>
using namespace std;
#define DATA_FILE1 "./Data_File"
#define SUCEESS 0
#define FAIL 1
[code].....
The code below is supposed to be a program that allows the user to enter in 2 matrices and add them together, and gives an error when they're not the same dimensions.
The error I'm getting is on line 11 of MAIN.CPP and is saying "The Variable has incomplete type 'Matrix'".
MAIN.CPP
#include <iostream>
#include <vector>
#include <string>
#include "Matrix Class Input.h"
using namespace std;
int main() {
Matrix A,B,C;
int r,c=0;
[Code] .....
for ex: say i'm declaring two variables under int type and some 3 under char,my output should be lyk this: 2 variables in int and 3 var of type char...(input to the main program is actually another program where these 2 int and 3 char are defined).
View 1 Replies View RelatedWhat is wrong with assigning a reference variable to another reference variable of the same type? I guess I have not understood references very well.
1- In below code, the initialization list gets error because agent "object reference variable" cannot be initialized with a reference variable of the same type.
Code:
class Intention {
public:
Intention(Agent& agent,int Id, string name);
[Code] ....
In other places I have the same problem. In below code the assignment gets error (no overloaded function for assigning a reference to another reference?)
Code:
void Agent::setWorld(World& world) {
this->world = world;
}
//Note: this->world has a type of World&
2- In this other one, I want to assign reference of a vector member to a reference variable of the same type.
Code:
vector<Intention> intentions;
...
Intention& currentIntention = intentions[intentionsIterator]
unsigned char key[32];
139 unsigned char rfseed[32];
173 f = fopen("/dev/urandom","rb");
174 fread(key,1,32,f);
175 fread(rfseed,1,32,f);
I am having problems copying outputs of the above code into other unsigned char other[32]. I need to keep the output of dev/urandom for backup. But, when I try to assign the values by memcpy(other, key, 32), the values do not match. The same problem happens by assigning values index by index in a loop.
#include<iostream>
using namespace std;
int main(){
int size_col = 12;
int size_row = 12;
char months_array[12][12] =
[Code] ....
I am having problems with passing a block of a char to a variable, so i could print it out.
It gives me an error: value of type *char cannot be assigned to a entity type char.