This is the output I expect
x |x|
1.2 1.2
-2.3 2.3
3.4 3.4
but I keep getting this:
x |x|
1.2 1.2
-2.3 2.3
3.4 3.4
Here is my part of code:
printf(" x |x|\n");
for (i = 1; i <= n; i++)
{
printf(" %.1f %.1f\n", array[i], array1[i]);
}
how do I change it?
You should specify a number before dot in %.1f that shows all the number including '-' for example:
printf("%3.1f",array[i]);
Will result in :
x |x|
1.2 1.2
-2.3 2.3
3.4 3.4
It means that a number should fill 3 places in screen.
Sorry for bad English.
Related
For a terminal application written in C I need to plot (in the terminal) two tables as line plots. To do this I use (following e.g. gnu tutorial)
FILE *gnuplot = popen("gnuplot", "w");
...
fprintf(gnuplot, "plot '-' u 1:2 t 'data1' w lp lt 0\n");
for (int i = 0; i < lines; ++i) {
fprintf(gnuplot,"%f %f \n", x[i] - x[0], y[i]);
}
fprintf(gnuplot, "\n");
fprintf(gnuplot, "t 'data2' lt 2\n");
for (int i = 0; i < lines; ++i) {
fprintf(gnuplot,"%f %f \n", x[i] - x[0], 0.4*(x[i] - c0)/c1);
}
fprintf(gnuplot, "e\n");
fflush(gnuplot);
The problem is that the data is plotted as one data block instead of two different ones. I expected to have a separation by using the line
fprintf(gnuplot, "t 'data2' lt 2\n");
which seems not to be the case. What is wrong in this code?
You probably want to do the following. Each inline data has to be terminated by an e.
In gnuplot console it would be:
plot '-' u 1:2 t 'data1' w lp lt 0, '' u 1:2 t 'data2' lt 2
1 0.1
2 0.2
3 0.3
4 0.4
e
11 0.5
12 0.6
13 0.7
14 0.8
e
Check help inline data and help special-filenames.
Although, to my opinion it is a bit confusing and suitable examples are missing. Maybe you can find them elsewhere.
My C program is ending on it's own and I can't figure out the issue. I have added a comment above the loop where it is stopping.
I am creating a program to match dna samples in arrays with each other. The dna samples are floats and I am reading them from a file.
This is the file I am reading from:
2.3 3.3 4.5 6.7 7.8 2.1 3.2 4.3 5.2 6.5
5
2.3 3.3 4.5 6.7 7.8 2.1 3.2 4.3 5.2 6.5
1.3 0.3 9.5 8.7 5.8 4.1 3.2 2.3 6.2 6.9
6.3 9.3 4.3 6.4 7.5 2.9 3.0 4.1 5.3 6.5
6.1 9.4 4.5 6.6 7.4 2.8 3.2 4.4 5.0 6.0
2.3 3.3 4.5 6.6 7.8 2.2 3.2 4.3 5.2 6.5
The expected output is all the values will be printed (5 lines for the criminal samples) and the first line will be matched and the rest will not. However this is my output:
Reading chromosomes of the suspect.
2.3 3.3 4.5 6.7 7.8 2.1 3.2 4.3 5.2 6.5
Reading chromosomes of the criminals.
2.3 3.3 4.5 6.7 7.8 2.1 3.2 4.3 5.2 6.5
1.3 0.3 9.5 8.7 5.8 4.1 3.2 2.3 6.2
I have attempted debugging it and at one point it was randomly assigning my sizeR variable to like 10000 or something during the loop and I assumed that was the problem somewhere but now it's not I'm struggling to understand why it is still stopping for me.
Code:
#include <stdio.h>
#include <stdbool.h>
FILE *fp;
int main(){
fp = fopen("dna_input.txt", "r");
int sizeR = 0, sizeC = 10; // declare size variables
float suspect[sizeC]; // declaring suspect array
float criminal[sizeR][sizeC]; // declaring criminal array
// reads 10 input values from first line of the file
printf("Reading chromosomes of the suspect. \n");
for (int i = 0; i < sizeC; i++){
fscanf(fp, " %f", &suspect[i]);
printf("%.1f ", suspect[i]);
}
printf("\n");
// reads integer from 2nd line of file for the amount of lines to read for next loop
fscanf(fp, " %d", &sizeR);
printf("Reading chromosomes of the criminals. \n");
// read 10 input values into 5 criminal arrays
// THIS LOOP IS WHERE MY PROGRAM IS STOPPING <---------------------------------------------
for (int i = 0; i < sizeR; i++){
for (int j = 0; j < sizeC; j++){
fscanf(fp, " %f", &criminal[i][j]);
printf("%.1f ", criminal[i][j]);
}
printf("\n");
}
// check for match
bool match = true;
for (int i = 0; i < sizeR; i++){
for (int j = 0; j < sizeC; j++){
if (suspect[j] != criminal[i][j]){
match = false;
}
}
// display matching result
if (match)
printf("The two profiles match! \n");
else
printf("The two profiles don't match! \n");
}
fclose(fp);
return 0;
}
You need to dynamically allocate the criminals array.
//Here sizeR is 0 so you are declaring criminal[0][10]
float criminal[sizeR][sizeC]; // declaring criminal array
Typical buffer overflow problem.
Thank you for the comments, I missed that completely. I've moved my criminal array to be declared after the fscanf
// reads integer from file for the amount of lines to read
fscanf(fp, " %d", &sizeR);
// declare criminal aray
float criminal[sizeR][sizeC];
I've been working on an assignment for school, basically we're creating 2 arrays of random doubles, then sorting them using 3 different algorithms and printing the results. The output needs to be printed with 5 elements per line.
I've got this code:
//print sorted arrayB
for (i = 0; i < size; i++)
{
printf ("%.1lf ", arrayB[i]);
if (i % 5 == 0 && i > 0)
{
printf ("\n");
}
}
where all variables are defined before the sort, and my output looks like this every time:
1.0 2.0 3.0 4.0 5.0 6.0
7.0 8.0 9.0 10.0 11.0
12.0 13.0 14.0 15.0 16.0
17.0 18.0 19.0 20.0 21.0
etc...
I don't understand why it's printing 6 elements in the top row, and 5 in all the rest. Any help is greatly appreciated!
Just write the evaluation by hand for your conditional:
if (i % 5 == 0 && i > 0)
i result
0 false
1 false
2 false
3 false
4 false
5 true
6 false
Now we can see that it is false 5 times, then true, which makes it print a newline, but only after you printed the number!
So you need to rearrange your logic slightly, but the conditional is correct.
The point is in the && i > 0 part of the if statement. If you'd remove it, this would be the output:
1.0
2.0 3.0 4.0 5.0 6.0
7.0 8.0 9.0 10.0 11.0
12.0 13.0 14.0 15.0 16.0
17.0 18.0 19.0 20.0 21.0
etc...
By excluding zero, you have prevented printing the newline after the first number, see?
The solution is to move the i index by one, like this:
if ((i + 1) % 5 == 0)
{
printf ("\n");
}
Now you don't even need the && i > 0 part, because i + 1 will never be zero.
You need to update the \n condition as below -
if ((i+1) % 5 == 0)
{
printf ("\n");
}
i % 5 will cause newlines after indices 5,10,15... This is your case where you have 6 at index 5, 11 at index 10..
Rather you need to break at 4,9,14... which are all covered by (i+1).
Just add 1 to i(therefore the condition i > 0, becomes unnecessary), which will solve. This occurs because in the condition imposed by you, for the first line break (\ n) to occur, it will have to go from 0 to 5, and to do so you will have to repeat the loop 6 times, so on the first line it showed 6 numbers , instead of 5
Like this:
#include <stdio.h>
#define SIZE 25
int main() {
int i, arrayB[SIZE] = {0};
for (i = 0; i < SIZE; i++)
{
printf ("%.1lf ", arrayB[i]);
if ((i+1) % 5 == 0)
{
printf ("\n");
}
}
return 0;
}
How can I force printf format codes like %f to produce aligned padded output for both positive and negative numbers. The following program is a minimal yet complete example of my problem:
#include<stdio.h>
#include<stdlib.h>
int main(int argc, char *argv[])
{
int step = 1;
float score = 0.1;
float phi = 0.1;
float rho = 0.2;
printf(" # score phi rho\n");
printf("%2d %2.3f %1.2f %1.2f\n", step, score, phi, rho);
step++;
score++;
phi++;
rho++;
printf("%2d %2.3f %1.2f %1.2f\n", step, score, phi, rho);
step++;
score -= 1.2;
phi++;
rho++;
printf("%2d %2.3f %1.2f %1.2f\n", step, score, phi, rho);
return 0;
}
and here is the result:
# score phi rho
1 0.100 0.10 0.20
2 1.100 1.10 1.20
3 -0.100 2.10 2.20
I wanted to have an output like
# score phi rho
1 +0.100 0.10 0.20
2 +1.100 1.10 1.20
3 -0.100 2.10 2.20
or
# score phi rho
1 0.100 0.10 0.20
2 1.100 1.10 1.20
3 -0.10 2.10 2.20
My current bad solution is an if-else statement conditioned on the sign of score variable to choose from two different printfs for plus and minus signs.
From the format specification syntax, the printf conversion specification follows
%[flags][width][.precision][size]type
So, if we set the flag directive to +, sign (+ or -) appears as a prefix of the output value. For example,
printf("%+5.2f\n%+5.2f\n", -19.86, 19.86); // prints -19.86 \newline +19.86
float batt = ((float)rand()/(float)(RAND_MAX)) * 5.0;
demo_printf("Battery:%.2f\n", batt);
From the line above , its doing a random numbers for batt. would like to ask how do i do about it to make it as a loop decreasing like very bit by bit . maybe per 0.1.
I cannot for loop the demoprint. i cannot . i can only loop elswhere
Huh?
This question is very strange. Do you mean something like this:
float batt = 5.f * rand() / RAND_MAX;
while(batt > 0.f)
{
printf("Battery is %.1f\n", batt);
batt -= 0.1f;
}
Sample output:
Battery is 4.2
Battery is 4.1
Battery is 4.0
Battery is 3.9
Battery is 3.8
Battery is 3.7
Battery is 3.6
Battery is 3.5
Battery is 3.4
[ ... more like this ...]
Battery is 1.0
Battery is 0.9
Battery is 0.8
Battery is 0.7
Battery is 0.6
Battery is 0.5
Battery is 0.4
Battery is 0.3
Battery is 0.2
Battery is 0.1
Battery is 0.0
// obtain initial random float
float batt = ((float)rand()/(float)(RAND_MAX)) * 5.0;
// iterate beginning with this random float downwards by steps of 0.1f
for (float x = batt; x > 0; x -= 0.1) {
demo_printf("Battery:%.2f\n", x);
}
Use 2 variables, target and current:
float current = 5.0f;
float target = 2.5f;
while(current > target) {
// print here
current -= 0.1f;
}
current = target;
// final print here
Just be aware that conversion of float literal constant 0.1f to binary float will never be perfectly accurate, and the decrement will not be exactly 0.1. But fixing that is for another question.