C++ sqrt function returning truncated (wrong) output [duplicate]
This question already has an answer here:
Integer division always zero [duplicate]
1 answer
I have a doubt on the function sqrt of math.h
I was debugging some code, and I figured out that my function was not working properly, as the square root of 2/3 was always returning zero.
I tried to isolate the problem by just writing down some square root calculations in a separate file, and the function isn't returning the correct values.
Am I missing something?
#include <math.h>
#include <iostream>
using namespace std;
int main(){
cout << sqrt(2/3) << endl;
cout << sqrt(16/2) << endl;
cout << sqrt(9/2) << endl;
return 0;
}
This is the output I receive:
0
2.82843
2
When the correct output should be:
0.81650
2.82843
2.12132
Thank you in advance.
c++ math.h
asked Nov 12 '18 at 17:14
Michele Fattoruso
3315
marked as duplicate by NathanOliver c++
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Nov 12 '18 at 17:18
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
|
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This question already has an answer here:
Integer division always zero [duplicate]
1 answer
I have a doubt on the function sqrt of math.h
I was debugging some code, and I figured out that my function was not working properly, as the square root of 2/3 was always returning zero.
I tried to isolate the problem by just writing down some square root calculations in a separate file, and the function isn't returning the correct values.
Am I missing something?
#include <math.h>
#include <iostream>
using namespace std;
int main(){
cout << sqrt(2/3) << endl;
cout << sqrt(16/2) << endl;
cout << sqrt(9/2) << endl;
return 0;
}
This is the output I receive:
0
2.82843
2
When the correct output should be:
0.81650
2.82843
2.12132
Thank you in advance.
c++ math.h
asked Nov 12 '18 at 17:14
Michele Fattoruso
3315
marked as duplicate by NathanOliver c++
Users with the c++ badge can single-handedly close c++ questions as duplicates and reopen them as needed.
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Nov 12 '18 at 17:18
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
2
There's a dup somewhere...
– YSC
Nov 12 '18 at 17:15
@YSC if you can find it, that would be really helpful. Couldn't find anything beside someone saying that sqrt(3) was evalued as zero in gdb
– Michele Fattoruso
Nov 12 '18 at 17:17
@YSC more like+Infdupes, to keep in spirit with IEEE 754
– SergeyA
Nov 12 '18 at 17:17
1
Does stackoverflow.com/questions/9764677/… answers your question?
– YSC
Nov 12 '18 at 17:17
2
@MicheleFattoruso there is nothing to be ashamed of. The intricacies of arithmetic are one of the most counter-intuitive parts of C/C++.
– SergeyA
Nov 12 '18 at 17:22
|
show 3 more comments
This question already has an answer here:
Integer division always zero [duplicate]
1 answer
I have a doubt on the function sqrt of math.h
I was debugging some code, and I figured out that my function was not working properly, as the square root of 2/3 was always returning zero.
I tried to isolate the problem by just writing down some square root calculations in a separate file, and the function isn't returning the correct values.
Am I missing something?
#include <math.h>
#include <iostream>
using namespace std;
int main(){
cout << sqrt(2/3) << endl;
cout << sqrt(16/2) << endl;
cout << sqrt(9/2) << endl;
return 0;
}
This is the output I receive:
0
2.82843
2
When the correct output should be:
0.81650
2.82843
2.12132
Thank you in advance.
c++ math.h
asked Nov 12 '18 at 17:14
Michele Fattoruso
3315
This question already has an answer here:
Integer division always zero [duplicate]
1 answer
I have a doubt on the function sqrt of math.h
I was debugging some code, and I figured out that my function was not working properly, as the square root of 2/3 was always returning zero.
I tried to isolate the problem by just writing down some square root calculations in a separate file, and the function isn't returning the correct values.
Am I missing something?
#include <math.h>
#include <iostream>
using namespace std;
int main(){
cout << sqrt(2/3) << endl;
cout << sqrt(16/2) << endl;
cout << sqrt(9/2) << endl;
return 0;
}
This is the output I receive:
0
2.82843
2
When the correct output should be:
0.81650
2.82843
2.12132
Thank you in advance.
This question already has an answer here:
Integer division always zero [duplicate]
1 answer
c++ math.h
c++ math.h
asked Nov 12 '18 at 17:14
Michele Fattoruso
3315
asked Nov 12 '18 at 17:14
Michele Fattoruso
3315
asked Nov 12 '18 at 17:14
Michele Fattoruso
3315
asked Nov 12 '18 at 17:14
Michele Fattoruso
3315
asked Nov 12 '18 at 17:14
Michele Fattoruso
3315
3315
marked as duplicate by NathanOliver c++
Users with the c++ badge can single-handedly close c++ questions as duplicates and reopen them as needed.
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Nov 12 '18 at 17:18
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
marked as duplicate by NathanOliver c++
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Nov 12 '18 at 17:18
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
2
There's a dup somewhere...
– YSC
Nov 12 '18 at 17:15
@YSC if you can find it, that would be really helpful. Couldn't find anything beside someone saying that sqrt(3) was evalued as zero in gdb
– Michele Fattoruso
Nov 12 '18 at 17:17
@YSC more like+Infdupes, to keep in spirit with IEEE 754
– SergeyA
Nov 12 '18 at 17:17
1
Does stackoverflow.com/questions/9764677/… answers your question?
– YSC
Nov 12 '18 at 17:17
2
@MicheleFattoruso there is nothing to be ashamed of. The intricacies of arithmetic are one of the most counter-intuitive parts of C/C++.
– SergeyA
Nov 12 '18 at 17:22
|
show 3 more comments
2
There's a dup somewhere...
– YSC
Nov 12 '18 at 17:15
@YSC if you can find it, that would be really helpful. Couldn't find anything beside someone saying that sqrt(3) was evalued as zero in gdb
– Michele Fattoruso
Nov 12 '18 at 17:17
@YSC more like+Infdupes, to keep in spirit with IEEE 754
– SergeyA
Nov 12 '18 at 17:17
1
Does stackoverflow.com/questions/9764677/… answers your question?
– YSC
Nov 12 '18 at 17:17
2
@MicheleFattoruso there is nothing to be ashamed of. The intricacies of arithmetic are one of the most counter-intuitive parts of C/C++.
– SergeyA
Nov 12 '18 at 17:22
2
2
There's a dup somewhere...
– YSC
Nov 12 '18 at 17:15
There's a dup somewhere...
– YSC
Nov 12 '18 at 17:15
@YSC if you can find it, that would be really helpful. Couldn't find anything beside someone saying that sqrt(3) was evalued as zero in gdb
– Michele Fattoruso
Nov 12 '18 at 17:17
@YSC if you can find it, that would be really helpful. Couldn't find anything beside someone saying that sqrt(3) was evalued as zero in gdb
– Michele Fattoruso
Nov 12 '18 at 17:17
@YSC more like
+Inf dupes, to keep in spirit with IEEE 754– SergeyA
Nov 12 '18 at 17:17
@YSC more like
+Inf dupes, to keep in spirit with IEEE 754– SergeyA
Nov 12 '18 at 17:17
1
1
Does stackoverflow.com/questions/9764677/… answers your question?
– YSC
Nov 12 '18 at 17:17
Does stackoverflow.com/questions/9764677/… answers your question?
– YSC
Nov 12 '18 at 17:17
2
2
@MicheleFattoruso there is nothing to be ashamed of. The intricacies of arithmetic are one of the most counter-intuitive parts of C/C++.
– SergeyA
Nov 12 '18 at 17:22
@MicheleFattoruso there is nothing to be ashamed of. The intricacies of arithmetic are one of the most counter-intuitive parts of C/C++.
– SergeyA
Nov 12 '18 at 17:22
|
show 3 more comments
1 Answer
1
active
oldest
votes
1,2,4,8,9 are integers constants, and the arithmetic result of integers will always be an integer.
Therefore, you should work with double constants, so you should try:
cout << sqrt(2.0/3.0) << endl;
cout << sqrt(16.0/2.0) << endl;
cout << sqrt(9.0/2.0) << endl;
answered Nov 12 '18 at 17:19
SHR
5,73562341
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
1,2,4,8,9 are integers constants, and the arithmetic result of integers will always be an integer.
Therefore, you should work with double constants, so you should try:
cout << sqrt(2.0/3.0) << endl;
cout << sqrt(16.0/2.0) << endl;
cout << sqrt(9.0/2.0) << endl;
answered Nov 12 '18 at 17:19
SHR
5,73562341
add a comment |
1,2,4,8,9 are integers constants, and the arithmetic result of integers will always be an integer.
Therefore, you should work with double constants, so you should try:
cout << sqrt(2.0/3.0) << endl;
cout << sqrt(16.0/2.0) << endl;
cout << sqrt(9.0/2.0) << endl;
answered Nov 12 '18 at 17:19
SHR
5,73562341
add a comment |
1,2,4,8,9 are integers constants, and the arithmetic result of integers will always be an integer.
Therefore, you should work with double constants, so you should try:
cout << sqrt(2.0/3.0) << endl;
cout << sqrt(16.0/2.0) << endl;
cout << sqrt(9.0/2.0) << endl;
answered Nov 12 '18 at 17:19
SHR
5,73562341
1,2,4,8,9 are integers constants, and the arithmetic result of integers will always be an integer.
Therefore, you should work with double constants, so you should try:
cout << sqrt(2.0/3.0) << endl;
cout << sqrt(16.0/2.0) << endl;
cout << sqrt(9.0/2.0) << endl;
answered Nov 12 '18 at 17:19
SHR
5,73562341
answered Nov 12 '18 at 17:19
SHR
5,73562341
answered Nov 12 '18 at 17:19
SHR
5,73562341
answered Nov 12 '18 at 17:19
SHR
5,73562341
5,73562341
add a comment |
add a comment |
2
There's a dup somewhere...
– YSC
Nov 12 '18 at 17:15
@YSC if you can find it, that would be really helpful. Couldn't find anything beside someone saying that sqrt(3) was evalued as zero in gdb
– Michele Fattoruso
Nov 12 '18 at 17:17
@YSC more like
+Infdupes, to keep in spirit with IEEE 754– SergeyA
Nov 12 '18 at 17:17
1
Does stackoverflow.com/questions/9764677/… answers your question?
– YSC
Nov 12 '18 at 17:17
2
@MicheleFattoruso there is nothing to be ashamed of. The intricacies of arithmetic are one of the most counter-intuitive parts of C/C++.
– SergeyA
Nov 12 '18 at 17:22