- #1
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I don't think that so many significant digits are needed 
Insights Rating: Is Precision Necessary?
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- Thread starter DrClaude
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In summary, there was a discussion about the number of significant digits needed and the precision of floating point numbers in PHP. The default value is 14, but someone changed it to 17, causing issues. It was suggested to revert back to 14 or even lower to 3 or 2. One person questioned why the default value is 14 and suggested that it may not be suitable for scientists or engineers. It was also mentioned that the function printf can be used to format decimal places in a number. Overall, it is believed that the default value of 14 is a good balance for most cases.
- #2
berkeman
Mentor
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- 20,177
Plus, the math looks wrong...
- #3
Drakkith
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Precision is important...
- #4
- 19,450
- 10,040
I changed the number of significant digits displayed in floating point numbers from 14 to 17. Might be what caused this issue. I'll revert back to 14.
- #5
mfb
Mentor
- 37,141
- 13,983
Change it to 3 or 2? There is no point in having more.
- #6
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Default is 14, so there must be some reason the PHP devs think it's a good value.mfb said:
- #7
berkeman
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I'm guessing that their Focus Group didn't have any scientists or engineers...Greg Bernhardt said:
- #8
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http://php.net/manual/en/function.round.php
from http://php.net/manual/en/function.printf.php
from http://php.net/manual/en/function.printf.php
Code:
You can use this function to format the decimal places in a number:
$num = 2.12;
printf("%.1f",$num);
prints:
2.1- #9
mfb
Mentor
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Well, if it is a general PHP setting: PHP has no idea how precise these numbers are supposed to be. 14 is small enough to avoid displaying rounding errors in most cases, and large enough to keep more digits than anyone is reasonably interested in (with extremely few exceptions).Greg Bernhardt said:
Related to Insights Rating: Is Precision Necessary?
1. What is the purpose of an insights rating?
An insights rating is used to evaluate the quality and validity of research and data analysis. It helps determine the level of precision and accuracy in the findings and conclusions.
2. Is precision necessary for all types of research?
While precision is important in most types of research, it may not be necessary for all studies. Some studies may focus more on qualitative data rather than quantitative data, in which case precision may not be as critical.
3. How is precision measured in research?
Precision is measured by the level of detail and accuracy in the data collected and analyzed. This can include factors such as sample size, data collection methods, and statistical analysis techniques.
4. Can a study still have value if it lacks precision?
Yes, a study can still have value even if it lacks precision. While precision is important for establishing the reliability and validity of a study, it is not the only factor that determines the usefulness and importance of research.
5. How can researchers ensure precision in their studies?
To ensure precision in their studies, researchers should carefully design their studies, use appropriate data collection and analysis methods, and properly assess and report their findings. Peer review and replication studies can also help validate the precision of research.
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