Rounding to a certain number of decimal places
- To: mathgroup at smc.vnet.net
- Subject: [mg119265] Rounding to a certain number of decimal places
- From: Andrew DeYoung <adeyoung at andrew.cmu.edu>
- Date: Fri, 27 May 2011 06:14:20 -0400 (EDT)
Hi, I would like to be able to round a number to a certain, specified number of decimal places (not number of digits), including zeros. Suppose that some function f does this, and takes two arguments, the number to be rounded and the number of decimal places to which to round: f[number, numPlaces]. Then, for example, I would like the following results, if possible: f[0.8168, 3] = 0.817 f[1.8168, 3] = 1.817 f[10.8168, 3] = 10.817 f[100.8168, 3] = 100.817 f[0.99, 3] = 0.990 f[0.9, 3] = 0.900 f[0.00572, 3] = 0.006 Is there a function f (either built-in or a custom function) that can do this? Mathmatica's built-in function NumberForm does not quite do this because the user specifies the number of digits, not the number of decimal places. Also, NumberForm does not count zeros after the decimal point as digits, nor does it add extra zeros as needed if they are redundant. Am I getting into deep water here, or is there something straightforward that can do what I would like? I am running Mathmatica 7. Also, I do not need to be able to do further computations on the output; I will be converting the output to a string, anyway. Thank you very much for your time. Andrew DeYoung Carnegie Mellon University