exponent

How to limit the decimal place to 4 in javascript with this type of values? the e is the exponent since I am using power of ten values. toFixed() doesn't seem to work. 1.0531436913408342e-7 -5.265718456704172e-7 8.425149530726674e7 Try: Math.round(val*10000)/10000 Jiri Kriz Try this method: value.toPrecision(1 + 4) for 4 decimal digits. There's actually a javascript method specifically for limiting the number of decimal places to show in exponential notation : *numObj*.toExponential([*fractionDigits*]) Using your example numbers you get: 1.0531436913408342e-7.toExponential(4) // returns 1

I have a dataset that abbreviates numerical values in a column. For example, 12M mean 12 million, 1.2k means 1,200. M and k are the only abbreviations. How can I write code that allows R to sort these values from lowest to highest? I've though about using gsub to convert M to 000,000 etc but that does not take into account the decimals (1.5M would then be 1.5000000). So you want to translate SI unit abbreviations ('K','M',...) into exponents, and thus numerical powers-of-ten. Given that all units are single-letter, and the exponents are uniformly-spaced powers of 10**3, here's working code

I have an array in python that contains a set of values, some of them are 2.32313e+07 2.1155e+07 1.923e+07 11856 112.32 How do I convert the exponential formats to the decimal format Additional: Is there a way I can convert the exponent directly to decimal when printing out in UNIX with awk? I imagine you have a list rather than an array, but here it doesn't make much of a difference; in 2.6 and earlier versions of Python, something like: >>> L = [2.32313e+07, 2.1155e+07, 1.923e+07, 11856, 112.32] >>> for x in L: print '%f' % x ... 23231300.000000 21155000.000000 19230000.000000 11856.000000

I've been trying to write a simple function in Java that can calculate a number to the nth power without using loops. I then found the Math.pow(a, b) class... or method still can't distinguish the two am not so good with theory. So i wrote this.. public static void main(String[] args) { int a = 2; int b = 31; System.out.println(Math.pow(a, b)); } Then i wanted to make my own Math.pow without using loops i wanted it to look more simple than loops, like using some type of Repeat I made a lot of research till i came across the commons-lang3 package i tried using StringUtils.repeat So far I think

Outline of problem: Please note I will abuse the life out of ^ and use it as a power symbol, despite the caret symbol being the bitwise XOR operator in JS. Take a list of positive integers, [ x_0, x_1, ..., x_n ] and find the last digit of the equation given by x_0 ^ ( x_1 ^ (... ^ x_n ) ... ) I'll call this function LD(...) for the rest of this question. Example: For a list of integers a = [2, 2, 2, 2] and given that 2 ^ (2 ^ (2 ^ 2)) = 65536 , it's easy to see that LD(a) = 6 . Note that 0 ^ 0 === 1 for this question, consistent with x ^ 0 === 1 , but not with 0 ^ x === 0 . What I've achieved

And no, this does not (to my understanding) involve integer division or floating-point rounding issues. My exact code is: static void Main(string[] args) { double power = (double)1.0 / (double)7.0; double expBase = -128.0; System.Console.WriteLine("sanity check: expected: -128 ^ 0.142857142857143 = -2. actual: " + expBase + " ^ " + power + " = " + Math.Pow(expBase, power)); System.Console.ReadLine(); } The output is: sanity check: expected: -128 ^ 0.142857142857143 = -2. actual: -128 ^ 0.14285 7142857143 = NaN The Target Framework for this code is (according to solution properties) .NET

I have a application which needs to raise a number to a fractional power. The target platform is an FPGA and I can get estimates on an FPU size for it, but I need an algorithm for raising a number to a fractional power just for a feasibility study. I'm assuming floating point as a worst case, I expect in practice we will be able to use short cuts, but for now I want to show that worst case can be implemented on our part. Thought I'd ask here and see if there were any common methods that I could checkout. I know there are software methods of doing this, I want just a reasonably efficient

I am wondering whether the following floating point notation is a valid JSON notation: "result":{"base_fee":1e-005} or should the exponent notation be replaced with a decimal notation? It is valid according to the format available at json.org as numbers can optionally have a base 10 exponent denoted by an E, uppercase or lowercase, an optional plus or minus, and one or more digits. It's perfectly valid, according to RFC 4627 RFC 7159 *: The representation of numbers is similar to that used in most programming languages. A number contains an integer component that may be prefixed with an