Questions about interpretation of numeric input or how Mathematica stores and manipulates numbers internally.

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1
vote
1answer
40 views

Calculations after NumberForm [duplicate]

As specified in documentation center the functions AccountingForm, NumberForm, etc. are useful only to display numbers in ...
1
vote
1answer
39 views

NumberLinePlot: How to make the 3rd list (c) appears with “black crosses” or “void circles”?

a = {1, 2, 5, 2} b = {2} c = {1.75, 2.88, 3.25} NumberLinePlot[{a, b, c}, PlotStyle -> Directive[PointSize[0.032]]] I thought about PlotMarkers or PlotStyle, ...
2
votes
1answer
48 views

How to insert a character in a string with condition?

Considering we have a string: str = "1a 789 4/7 123/7 asff %$#7 478 9/4" How can I insert "/1" for the numbers that are ...
1
vote
1answer
180 views

Something wrong with FromDigits?

NestList[RotateLeft, IntegerDigits[19], 1] FromDigits[%] (* WRONG *) ...
0
votes
0answers
50 views

How to parse fraction to a number?

Considering a fraction: val = "F \!\(\*FractionBox[\(1\), \(1\)]\)"; I extract the part of interest: ...
2
votes
1answer
65 views

Converting a quantity to a decimal form [closed]

I have a function giving me this: (5 Coulomb)/(6 Second) as output. I want this in decimal form and would like to have the variables taken off the end for unit ...
10
votes
5answers
217 views

Tidy form of numbers with errors using ScientificForm

Say I've computed something and got a number 0.02112398 with a computed error: 0.000331 Formatting it with ScientificForm[0.02112398 \[PlusMinus] 0.000331] gives ...
1
vote
0answers
56 views

How can I perfect this game for Wolfram Demonstration publication? [closed]

When the messages change the window inactivates, and when I try to host an interactive CDF on my site it turns red and says something about numbers having to be scaled or offset. Any help? I'm ...
0
votes
1answer
77 views

Why does my function return an expression rather than a number? [closed]

I feel like I'm going insane. I have a function $f(x)=e^{-x^2}$ which I need to evaluate using forward, backward and central first order finite differences with intervals ...
0
votes
1answer
49 views

How to “de rationalize” a number? [closed]

How can 1/2 be represented as 0.5? Thanks!
4
votes
3answers
214 views

What is the FullForm of 36^^sadjh.87s567*^-34?

The Mathematica parser parses and computes number literals before sending them to FullForm even if Hold is applied. Thus the ...
1
vote
2answers
81 views

Arithmetic on algebraic numbers

I'd like to perform some elementary operations on algebraic numbers. ...
4
votes
3answers
185 views

How can I improve NumberString?

I would like to test strings to see if they represent numbers. This should include number representations with precision marks and scientific notation. NumberString ...
1
vote
3answers
93 views

Is there a global setting for number form

I'm creating strings which represent equations in C to use with library link. The problem I have is that numbers in ScientificForm are no longer useful after they ...
2
votes
3answers
97 views

Testing for a vector of reals [closed]

Suppose I define: RealVector[expr_]:=VectorQ[expr,NumberQ[#]&&Head[#]===Real)]; Then: ...
21
votes
3answers
546 views

Real Numbers in the Wolfram Language

Epilog: Much of the discussion in the answers below revolves around the distinction between Real as a data type and real numbers as a domain or class of numbers (irrespective of the form in which ...
4
votes
1answer
181 views

Mod[1.2, 0.2] is not equal to zero

Why doesn't the following expression evaluate to zero? In[1]:=Mod[1.2, 0.2] Out[1]=0.2 Edit: This is what I wanted to do: ...
1
vote
2answers
165 views

create a function that converts a character string consisting of lowercase letters of the english alphabet to a number

I need a function that will take input as a string of lowercase letters and then output integers in this form a=01 b=02 c=03 d=04 e=05 . . . z=27 The letters must correspond with these integers ...
5
votes
2answers
129 views

Display All Output Numbers in HEX

How might I modify Mathematica such that I can get the following functionality when working with HEX values. The odd lines are input and the even output. Red values should be the HEX values. ...
2
votes
1answer
68 views

Range and decimal digits [duplicate]

When I set Plot[Sin[x], {x, -2, -1}, Frame -> True, Axes -> False, FrameTicks -> {{Automatic, Automatic}, {Range[-2, -1, 0.2], Automatic}}] I ...
6
votes
7answers
187 views

Join decimal part

I have a list of mesures that each vector is like {0,1,-2,259} but it should be like {0.1,-2.259} So I did a rule, like ...
1
vote
1answer
90 views

How can I export numerical data in a calculation-favorable format?

I am exporting some data into the txt file but since the values exported to this txt file expresses 10^6 to be *^6, I cannot use these numbers in calculations in other programs.. For instance, when I ...
0
votes
0answers
58 views

Balanced n-ary Base Representation

This may be a repeat question, but I was wondering how one would implement the expression/calculation of a representation of a given number h in base balanced n-ary, where n>1 is odd. (For example, ...
3
votes
3answers
291 views

Customizing decimal mark used in plot frame tick labels

I am using the Plot function in a usual way. I use Mathematica 9.0.1.0 in English (I do not know if it is available in other languages, but I do not mind), and as a ...
3
votes
1answer
105 views

Is there a `Real` equivalent to `FromDigits`?

One can extract an Integer's digits using IntegerDigits and reassemble them into the Integer ...
13
votes
4answers
2k views

How to implement Donald Knuth's up-arrow notation

How does one enter very large numbers in up-arrow notation? Up-arrow notation was created by Donald Knuth to write very large numbers in it iterated exponentiation form, for example 6↑↑3 = 6^6^6.
0
votes
1answer
161 views

Converting strings of the form “1.34e5” to real numbers? [duplicate]

ToExpresssion doesn't understand real numbers of the form "1.34e5". How do I convert the string ...
6
votes
1answer
183 views

Machine Epsilon

I'm trying to evaluate the machine epsilon of my computer (see below). I wrote this: ...
1
vote
0answers
140 views

How to work with large numbers

How do I browse very large numbers in mathematica, say $10^{{10}^{{10}^{1.414\ldots}}}$? By browse I mean finding the $k$th decimal place before or after the decimal point. Everything I have tried ...
0
votes
2answers
134 views

The precision of the number

I have problem in Mathematica with unnecessary rounding which is caused by high precision. For example I have value a = 2.052685846*10^-1865, when I make ...
0
votes
1answer
68 views

Square root of a value defined in a finite field?

I am trying to find the right way to compute the square root of a number defined in a finite field. For example, ...
5
votes
0answers
125 views

NMinimize seems to call function with the same values multiple times

I have to minimize a function where the evaluation of one parameter set takes very long (around 5sec) and discovered alongside, that NMinimize seems to call this ...
2
votes
2answers
421 views

Enter exact rational numbers easily with decimal notation

Is there a simple way to enter decimal numbers such as 0.123 so that Mathematica interprets it as an exact rational number 123/1000?
0
votes
2answers
63 views

Function that returns the binary string given its index in lexicographic ordering

Index the binary strings in lexicographic order, so that the empty string " " corresponds to 0, the string "0" corresponds to 1, the string "1" to 2, and so on. I want a function that, given a ...
5
votes
2answers
140 views

Showing AlgebraicNumber[1/2 (1 + Sqrt[5]), {-3, 2}] in human-readable way

Is there a function to show algebraic numbers in Mathematica more conveniently? I am looking for something similar to MatrixForm for matrices. For example, I would like to view ...
0
votes
0answers
75 views

Formatting numbers for sending to the WolframAlpha[] function

I have a function that gives me a number of meters; how do I attach "meters" to it and send it to WolframAlpha? The function generating the result isn't a unit-aware calculation or anything: ...
8
votes
1answer
4k views

Entering numbers in Scientific Notation?

I need to play with a lot of powers such as 10^-3. 1E-3 does not work for it. Is there any short form for it?
1
vote
1answer
73 views

Avoid unnecessary truncation

Is there any way to change the general settings in Mathematica so that when I type e.g. 0.34*60000000 I get the output ...
8
votes
4answers
1k views

How to plot logarithmic scales

How can a simple logarithmic number line be drawn between any 2 integer values? The closest function I found in the documentation is LogLinearPlot[] and I've ...
2
votes
2answers
95 views

How to interpret and show an input number with the amount of significant digits given?

what can I do to have Mathematica intepret and show a number with exactly the amount of digits I gave as an input? I have a larger talbe with numbers (text file, whitespace seperated) which are ...
-5
votes
1answer
391 views

random number visualization without generator (Spectral Test)

Does anyone have codes for using only numbers to make this kind of random-number visualization and not requiring a number generator? ...
47
votes
2answers
2k views

When I can assume that all decimal digits returned by Mathematica are provably correct?

How to Control the Precision and Accuracy of Numerical Results Arbitrary-Precision Numbers Mathematica works with exact numbers and with two different types of approximate numbers: ...
0
votes
1answer
155 views

Finite precision - how to get rid of “near zeros” [duplicate]

I am performing a finite-precision operation on a matrix A which I know precisely; call the result B. The operation is taking ...
9
votes
3answers
739 views

Expression of uncertainty in measurement.

I have a problem with writing a Mathematica function. I have been requested to show the results of my experiments with the measurement uncertainty (mu) like below: ...
8
votes
1answer
1k views

How do I get Mathematica to show a number in non-exponential form? [duplicate]

Sometimes I make a calculation in Mathematica that produces a big number, which Mathematica shows like so: -1.52522*10^7 This is annoying to me, because I want ...
8
votes
1answer
200 views

Is it possible to lower the bitwidth of (floating point) numbers?

The answer to this question will most probably be a definite no. Nevertheless, I would like to know whether it is possible to represent reals in the memory on less than the standard 32 or 64 bits ...
-1
votes
1answer
287 views

How can I change the default output number form to accounting form?

By default, large numbers are displayed in scientific form in output like 1.2345 x 10^8 in Mathematica 8.0.4, but I would prefer having numbers in accounting form ...
1
vote
1answer
218 views

Number with no decimal mark

I'm using Mathematica to create some images and labeling them after a simple calculation done previously. As the name of the file depends on the result, I want to show it with no decimal separator ...
11
votes
1answer
637 views

Number format in Legend Labels

I would like to use the usual (new and nice) BarLegend[] with something like BarLegend[{"LakeColors", 1/10000 {-2, 2}}] which ...
5
votes
2answers
463 views

Fast Karatsuba Squaring, how to?

I want to improve timing of squaring for big numbers. So I asked What is the fastest way to split a number into parts and What is the most efficient way to add zeros to end of a number with several ...