A statement that the values of two expressions are equal indicated by the sign = .
A statement that the values of two expressions are equal indicated by the sign =.
Questions tagged [equation]
1925 questions
21
votes
3 answers
General - Is there a way to calculate an average based off of an existing average and given new parameters for the resulting average?
Lets say, we're calculating averages of test scores:
Starting Test Scores: 75, 80, 92, 64, 83, 99, 79
Average = 572 / 7 = 81.714...
Now given 81.714, is there a way to add a new set of test scores to "extend" this average if you don't know the…
thepip3r
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21
votes
5 answers
Calculate the position of an accelerating body after a certain time
How do I calculate the position of an accelerating body (e.g. a car) after a certain time (e.g. 1 second)?
For a moving body that it not accelerating, it is a linear relationship, so I presume for an accelerating body it involves a square…
Iain
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20
votes
5 answers
Algebra equation parser for java
I need a library to be able to parse an equation an give me the result giving the inputs.
For example something like this:
String equation = "x + y + z";
Map vars = new HashMap();
vars.add("x", 2);
vars.add("y",…
Alfredo Osorio
- 11,297
- 12
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- 84
19
votes
3 answers
Calculating opacity value mathematically
How is opacity calculated mathematically?
There is opacity value in Photoshop, CSS etc. Actually this opacity is the transparent behavior of a layer. That we all know.
But how is it calculated mathematically? Is there any equation to calculate…
spider
- 320
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17
votes
6 answers
The shortest path between two integers by adding or subtracting
Here's the description of this problem:
You are given two integers a and b. You want to find the shortest sequence of operations necessary to transform a into b, where at each step you are allowed to add or subtract 5, 7, or 12.
For example, if…
Ivan
- 766
- 6
- 17
16
votes
5 answers
Mathematical equation manipulation in Python
I want to develop a GUI application which displays a given mathematical equation. When you click upon a particular variable in the equation to signify that it is the unknown variable ie., to be calculated, the equation transforms itself to evaluate…
Leafy
- 359
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15
votes
1 answer
Equation Parsing Library C++
I'm sure there must be something like this somewhere but I can't seem to find anything useful on here or Google. I had hoped Boost might have something but alas not.
What I'm after is a lightweight library that can take a string from the user, for…
Dan
- 12,857
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- 57
15
votes
5 answers
Plot equation showing a circle
The following formula is used to classify points from a 2-dimensional space:
f(x1,x2) = np.sign(x1^2+x2^2-.6)
All points are in space X = [-1,1] x [-1,1] with a uniform probability of picking each x.
Now I would like to visualize the circle that…
Elyakim
- 511
- 1
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15
votes
4 answers
Typesetting LaTeX fraction terms to be larger in an equation
I have the following formula in LaTeX, based on Fisher's Exact Test. (NOTE: requires the use of the amsmath package for \binom.)
\begin{equation}
P(i,j) = \sum_{x=|N(V_i) \cap V_j|}^{\min\{|V_j|, |N(V_i)|}
\frac{ \binom{|V_j|}{x} \binom{|V -…
gotgenes
- 38,661
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- 128
15
votes
8 answers
How to Solve Equations with java?
I have three equations like the following ones:
x + y + z = 100;
x + y - z = 50;
x - y - z = 10;
How can I find the values of x, y, and z with Java?
String equation1="x+y+z=100;";
String equation2="x+y-z=50;";
String equation3="x-y-z=10;";
int[]…
Cong De Peng
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13
votes
3 answers
Haskell: Equation Expander 1+(1+(1+(1+(…))))=∞
Does there exist a equation expander for Haskell?
Something like foldr.com: 1+(1+(1+(1+(…))))=∞
I am new to Haskell I am having trouble understanding why certain equations are more preferable than others. I think it would help if I could see the…
user295190
13
votes
3 answers
How can I split a string into tokens?
If I have a string
'x+13.5*10x-4e1'
how can I split it into the following list of tokens?
['x', '+', '13', '.', '5', '*', '10', 'x', '-', '4', 'e', '1']
Currently I'm using the shlex module:
str = 'x+13.5*10x-4e1'
lexer =…
Martin Thetford
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12
votes
5 answers
Safely evaluate simple string equation
I'm writing a program in which an equation is inputted as a string, then evaluated. So far, I've come up with this:
test_24_string = str(input("Enter your answer: "))
test_24 = eval(test_24_string)
I need both a string version of this equation and…
Aamri
- 139
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12
votes
2 answers
What are the state-of-art methods for solving functional equations?
Suppose that you want to find a λ-calculus program, T, that satisfies the following equations:
(T (λ f x . x)) = (λ a t . a)
(T (λ f x . (f x))) = (λ a t . (t a))
(T (λ f x . (f (f x)))) = (λ a b t . (t a b))
(T (λ f x . (f (f…
MaiaVictor
- 51,090
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- 286
12
votes
6 answers
RMSE (root mean square deviation) calculation in R
I have numeric feature observations V1 through V12 taken for a target variable Wavelength. I would like to calculate the RMSE between the Vx columns. Data format is below.
Each variable "Vx" is measured at a 5-minute interval. I would like to…
Vicki1227
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