significant-digits

I'm trying to write code in MATLAB that will round number to certain (as I ask) significant digits. I'm not sure how to do it. Any suggestions? To round to d significant digits : >> d = 3; %// number of digits >> x = 5.237234; %// example number >> D = 10^(d-ceil(log10(x))); >> y = round(x*D)/D y = 5.2400 To round to d decimal digits : >> d = 3; %// number of digits >> x = 5.237234; %// example number >> D = 10^d; >> y = round(x*D)/D y = 5.2370 EDIT Actually it's easier: the round function supports these options: >> d = 3; >> x = 5.237234; >> y = round(x, d, 'significant') y = 5.2400 >> d = 3;

I've come across two different precision formulas for floating-point numbers. ⌊(N-1) log 10 (2)⌋ = 6 decimal digits (Single-precision) and N log 10 (2) ≈ 7.225 decimal digits (Single-precision) Where N = 24 Significant bits (Single-precision) The first formula is found at the top of page 4 of " IEEE Standard 754 for Binary Floating-Point Arithmetic " written by, Professor W. Kahan . The second formula is found on the Wikipedia article " Single-precision floating-point format " under section IEEE 754 single-precision binary floating-point format: binary32 . For the first formula, Professor W.

I am plotting some big numbers with matplotlib in a pyqt program using python 2.7. I have a y-axis that ranges from 1e+18 to 3e+18 (usually). I'd like to see each tick mark show values in scientific notation and with 2 decimal places. For example 2.35e+18 instead of just 2e+18 because values between 2e+18 and 3e+18 still read just 2e+18 for a few tickmarks. Here is an example of that problem. import numpy as np import matplotlib.pyplot as plt fig = plt.figure() ax = fig.add_subplot(111) x = np.linspace(0, 300, 20) y = np.linspace(0,300, 20) y = y*1e16 ax.plot(x,y) ax.get_xaxis().set_major

I have some decimal data that I am pushing into a SharePoint list where it is to be viewed. I'd like to restrict the number of significant figures displayed in the result data based on my knowledge of the specific calculation. Sometimes it'll be 3, so 12345 will become 12300 and 0.012345 will become 0.0123. Occasionally it will be 4 or 5. Is there any convenient way to handle this? HAL9000 See: RoundToSignificantFigures by "P Daddy". I've combined his method with another one I liked. Rounding to significant figures is a lot easier in TSQL where the rounding method is based on rounding position

If I have a double (234.004223), etc., I would like to round this to x significant digits in C#. So far I can only find ways to round to x decimal places, but this simply removes the precision if there are any 0s in the number. For example, 0.086 to one decimal place becomes 0.1, but I would like it to stay at 0.08. The framework doesn't have a built-in function to round (or truncate, as in your example) to a number of significant digits. One way you can do this, though, is to scale your number so that your first significant digit is right after the decimal point, round (or truncate), then

How can you round any number (not just integers > 0) to N significant digits? For example, if I want to round to three significant digits, I'm looking for a formula that could take: 1,239,451 and return 1,240,000 12.1257 and return 12.1 .0681 and return .0681 5 and return 5 Naturally the algorithm should not be hard-coded to only handle N of 3, although that would be a start. Here's the same code in Java without the 12.100000000000001 bug other answers have I also removed repeated code, changed power to a type integer to prevent floating issues when n - d is done, and made the long