Skip to main content

Questions tagged [arithmetic]

Questions on arithmetic operations in Mathematica.

Filter by
Sorted by
Tagged with
4 votes
4 answers
219 views

Lines of intersections in a parabola

To test the parabolic sieve, my intention was for the graph to show the coordinates of two points on the parabola and the value of the intersection on the y-axis. A table with this information would ...
3 votes
2 answers
676 views

Recycle buying soda problem

there is a question: " If a bottle of soda costs \$1 and you can exchange two empty bottles for one soda, how many sodas can you drink with \$20 " ...
2 votes
2 answers
122 views

How can I enforce the use of Subtract and Divide?

It has been noted before, here and here, that when you enter a/b or a-b, Mathematica does not convert these to ...
4 votes
5 answers
496 views

How to check if multiplication requires carries?

For some purposes I need to know if there are there any carries in the multiplication of two numbers, especially in base-2. How can we do this in Mathematica? Thanks to all, very interesting answers! ...
5 votes
3 answers
547 views

How to find a longest word path in dictionary?

Cross post here A word path means the last character of the last word is same to the first character of the next word.And the path have no duplicated word.If I have $55$ words,I can find it with this ...
4 votes
1 answer
143 views

Simplify expressions with modulo 2 (Boolean algebra)

Suppose I have a (Boolean algebra) expression a = p1 x^2 + p2 x (x-1) + 3 p3 + 4 p4 x where p1, ..., ...
17 votes
3 answers
1k views

How to enter a repeating decimal in Mathematica

I don't understand how to manipulate numbers with repeating decimal in Wolfram Mathematica language. For example 0.3... does not work as input and I don't see how ...
13 votes
2 answers
306 views

Arithmetic operations on NumericArrays

Currently, NumericArrays are directly supported by the most important array-related functions, what makes them a very attractive data structure for implementing ...
0 votes
1 answer
63 views

How can I redefine multiplication this way?

I want the product of matrix objects to be evaluated to the matrix object of dot products of the arguments, but only if the matrices commute. Why this does not work? ...
4 votes
3 answers
3k views

Permanently rounding numbers/values to a given number of significant figures

I am searching for a simple way of rounding and setting an input to a desired number of significant figures. There are a vast number of posts that discuss similar problems, but none address this issue....
3 votes
1 answer
213 views

How can I redefine multiplication?

For instance, I want 0 Infinity = 0 I tried this: Unprotect[Times];Times[Infinity,0]=0;Times[0,Infinity]=0;Protect[Times]; But ...
1 vote
2 answers
181 views

Express rational and infinite expressions in Mathematica [closed]

I have several doubts about notation. I would appreciate any clarifications. a) I can express, for example, a periodic or semi-periodic number without writing it in its rational form. Can such ...
3 votes
0 answers
73 views

Problem with Mathematica Relationship Building

When I enter the following to get Mathematica to open my pod door I get Could someone try and replicate this? Also, my name is not Dave and I throw my own error... ...
-3 votes
1 answer
111 views

long division acurate answer on dividing long numbers [closed]

ok but first of all if i have the huge number to be divided what will i have to use for the division to be accurate long division or some other formula square root or 2 this is to calculate music ...
1 vote
1 answer
378 views

The square of Abs of a complex number

We all know that 4^2 + 22^2 = 500 Is there a natural way to generates 500 from the complex number ...
0 votes
0 answers
60 views

Ordinal arithmetic

How can I compute with ordinals in mathematica? For instance, I'd like to query $2+\omega > 1 + 2 \omega$.
2 votes
3 answers
723 views

Rounding Real number

I have real numbers in array, I want to round (or truncate) these numbers to 2-digit after decimal point, then I want to write values to Excel File For example if I have ...
5 votes
1 answer
249 views

Does Mathematica simplify calculation when encounter zero?

e.g. when Mathematica Calculating f[x0]=A[x0] B[x0], where A[x] & B[x] could be some complicated high dimensional function. Will Mathematica outcome 0 directly ...
1 vote
0 answers
25 views

Mathematica 12.1: Evaluation result does not show decimals [duplicate]

It surprises me that Mathematica does not show decimals after evaluating the following calculations: 500000+5.05 Result: 500005. Expecting: 500005.05 ...
2 votes
1 answer
164 views

How does Leafcount work? [closed]

I am curious about how LeafCount works because when I count the number of leaves in my solution to a Wolfram Challenge, I get a much smaller result than those listed on the leaderboard for Multiples ...
2 votes
2 answers
248 views

How to calculate percentage change using Dataset[]

With the following code, I can calculate percentage changes in selected indicators over time. The code is not efficient nor practical to integrate it into Manipulate...
37 votes
8 answers
3k views

Insert $+$, $-$, $\times$, $/$, $($, $)$ into $123456789$ to make it equal to $100$

Insert $+$, $-$, $\times$, $/$, $($, $)$ into $123456789$ to make it equal to $100$. Looks like a question for pupils, right? In fact, if the available math symbols are limited to addition ($+$), ...
0 votes
1 answer
716 views

How to multiply a vector by a scalar?

I'm plotting a simple 2D graph derived from 4 3D vectors: ...
42 votes
2 answers
1k views

Is there a difference between Divide[a,b] and a/b?

In this comment it was asserted that Divide[a,b] and a/b are different, though the documentation indicates that they are the ...
0 votes
2 answers
331 views

How to generate multiplication tables up to nxn?

I'm doing a simple multiplication table and I have this that I'm having a hard time with. I imagine that there must be a shorter way to do it, what I can't get is that it paints black the first column ...
7 votes
1 answer
177 views

Running Mathematica in 'SpouseMode'

In this previous question I looked into a deprecated capability of Mathematica from Version 2. Mathematica command that allows it to read my intentions Thanks to all for your answers. I note that ...
2 votes
1 answer
86 views

Can we change Mathematica's original number system for arithmetic mod p or other arithmetic systems?

It seems Mathematica has a standard arithmetic system that resembles real numbers. Can we change Mathematica's original number system for arithmetic mod p so that whenever we write expressions, it sum ...
3 votes
1 answer
166 views

Solving calculation puzzle [closed]

I recently got asked how to achieve a result of 100 only using the numbers {1,7,7,7,7} (the number 1 can be used only once and ...
18 votes
1 answer
1k views

How to prevent reduction of a fraction into lowest terms?

I have a question about the concept of simplification. I want to explain it with an example. When I write the fraction $4/8$ in Mathematica, the output is 1/2. How ...
1 vote
0 answers
74 views

Explanation on why this gives overflow?

If you have a phrase like $10^{0.00057 \cdot 10^{42}}$ that gives "overflow", what is the reason? Is it because, well, something about the size of this whole thing?
2 votes
0 answers
67 views

Should I redefine 0^0 [duplicate]

I've found some times, while playing with combinatorics, that Mathematica can't calculate some functions because $0^0$ is not defined as $1$. (I know that some people think that $0^0$ should be left ...
3 votes
2 answers
122 views

Can I make RandomInstance use exact arithmetic?

When using RandomInstance on a GeometricScene the answer loses precision when root objects are encountered. Is there a way to ...
2 votes
2 answers
64 views

LocalTime arithmetic

In an attempt to calculate the time difference between two cities I enter: ...
0 votes
0 answers
90 views

Why does Log[Abs[#]] return a complex number?

For a nonzero number $x$, $\log|x|$ should be a real number. Why does the following NestList contain non-real numbers when no numbers involved are close to zero? Is it a bug? ...
8 votes
4 answers
1k views

How to recover Pauli matrices properties in Mathematica?

I want to do a cross or dot product involving a vector of Pauli matrices $ \vec\sigma=(\sigma^1, \sigma^2, \sigma^3) $; for example, $ \vec\sigma\times\vec\sigma=2\mathrm i\vec\sigma $ and $ \vec\...
2 votes
1 answer
174 views

Why does this whole number have a recurring value? [duplicate]

I have a math question which that may seem simple to some but not to me if you where to do the calculation 12.30 * 12 it would equal 147.60 but why is that when I show the answer to more then two ...
3 votes
3 answers
161 views

Why does the Mathematica give different numerical results?

Why do the two inputs give different values? in:=(-y)^a /. a -> 2.99 /. y -> -2 out:=7.94474 and ...
3 votes
2 answers
88 views

Advice for making addition and multiplication tables for my kid

I'm working with my 6 year old on understanding and mastering addition. As a result, I want to be able to make some custom addition (and eventually multiplication) tables for her to fill out. ...
3 votes
2 answers
280 views

Applying Mod on list of list with outcomes +1, -1, other

I have a list lis = {{7, 8}, {17, 9}, {11, 10}, {12,10}} I want to apply Mod to each pair with output +1,-1 or ...
8 votes
3 answers
392 views

Improving Map Function on Lists

Dealing with spectral data (2D lists) where offsets (corresponding 1D list) must be removed from each individual spectrum. Looking for feedback on improvements over my current method. ...
3 votes
1 answer
115 views

Why Divide does not give the same answer? [closed]

I saw a question on Facebook $8\div2 (2 + 2)=?$ Consider these inputs. Divide[8, 2 (2 + 2)] 1 $8\div2 (2 + 2)$ using esc+div+esc 16 Why the results are ...
0 votes
2 answers
205 views

Mathematica doesn't evaluate/simplify arithmetic expression in its output [closed]

I have two matrices, A := {{1, 2, -4}, {2, -2, -2}, {-4, -2, 1}} and ...
0 votes
1 answer
96 views

Generating columns in table and header for exported data file automatically

I have a code that goes like this: ...
4 votes
0 answers
84 views

Force computation on IEEE float/double

I'm checking two different procedures that will eventually be used with regular floating point arithmetic. I need to estimate numerical error arising from floating point arithmetic. Is there a way to ...
4 votes
1 answer
476 views

multiply two vectors, component by component [closed]

Would like to take two vectors and multiply components at the same index.For example {a1, a2, a3} x {b1, b2, b3} to produce {a1 b1, a2 b2, a3 b3}. The following works, but are there some alternatives?...
3 votes
1 answer
145 views

Forcing divisions to be a machine-precision floating point divisions instead of multiplication by inverse

I want to imitate machine-precision, de facto IEEE division on Mathematica. On my quick trials I find this surprisingly hard to accomplish, since Mma rewrites a / b ...
2 votes
1 answer
212 views

How to form subgraphs from a connected graph

I have a connected graph with 72 nodes and its binary adjacency matrix. I need to find all possible connected subgraphs with exactly 6 nodes, i.e., I need to find all connected subgraphs and each ...
0 votes
3 answers
76 views

Roots of an algebraic expresion [duplicate]

If in WolframAlpha I put (-8)^(2/3) then it outputs the main root and 3 roots solution too (to the end in a polar graphic). How can I get the 3 root solution of <...
4 votes
2 answers
127 views

Raise a table of pre-existing data to the power of of one of the variables

NOTE: I have edited this question to give a table whose first elements don't count up from 0 to 5. I'm using a sample table ...
4 votes
1 answer
155 views

Machine Epsilon is not equal to $MachineEpsilon [duplicate]

I try to wrap my head around machine precision calculations in Mathematica (11.2, Linux). I do not understand the following behavior: ...