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Questions tagged [exponential]

Exponential can refer to a mathematics function, a curve / graph / dataset that follows the growth of that function, the exponential distribution in statistics, or a format to represent floats.

Exponential can refer to a mathematics function, a curve / graph / dataset that follows the growth of that function, the exponential distribution in statistics, or a format to represent floats.

Definitions from wikipedia:

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Calculating the exponential of a square matrix

I'm trying to write a method that calculates the exponential of a square matrix. In this instance, the matrix is a square array of value: [1 0] [0 10] and the method should return a value of: [e 0] [0 e^10] However, when I run my code, I get a…
ponsly
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Python exponential decay curve_fit gives me a linear fit

Hi I'm attempting to produce a fit for each of my three exponential decays. I am not successful with producing a satisfactory fit. This is what I get: https://i.stack.imgur.com/abRZa.png Any help is greatly appreciated. My code is below. import…
Richard Hsia
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Exponential Search Trees

How is exponential search done? According to http://en.wikipedia.org/wiki/Exponential_tree, "An exponential tree is almost identical to a binary search tree, with the exception that the dimension of the tree is not the same at all levels. In a…
user3195395
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Is it possible to evaluate a fraction of exponetial to sum of exponentials

I want to evaulate a fraction like this: or \begin{equation} \frac{e^{y_t}}{\sum_{i=1}^T{e^{y_i}}} \end{equation} for large y values. But a statistical software (e.g., R) can not evaluate exp(800) or even larger numbers. Then the problem is…
Glenn
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What is the fastest method for solving exp(ax)-ax+c=0 for x in matlab

What is the least computational time consuming way to solve in Matlab the equation: exp(ax)-ax+c=0 where a and c are constants and x is the value I'm trying to find? Currently I am using the in built solver function, and I know the solution is…
user2349373
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Why does this exponential equation return an all-zero array?

I am trying to figure out why I am getting all zeros back in the code below. a = 7.0e16; e = 100000; r = 8.3140; t = 253:2:325; k = a.*exp(-e./t.*r); k returns as 1x37 array consisting of only zeros. Is it because my numbers are too large or too…
user1757273
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How to order this computation for numerical stability?

I'm trying to compute a vector, whose sum is 1 and whose elements are defined as such: v[i] = exp(tmp[i])/exp(tmp).sum() The problem is that the value in the exponential may be large (between -10^2 and 10^2), making the exponential to evaluate to…
cpa
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How to convert BigDecimal to the exponential form?

How to convert BigDecimal object to a String representation that uses the exponential form? something like: 3.134e67? I looked into the API and I found toEngineeringString() but it does not give me what I want.
Eng.Fouad
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jQuery AJAX pagination how to prevent exponential looping?

I'm trying to create an ajax pagination with jQuery. I am getting it to work but with a massive problem: The pagination consists of <<-First <-Previous Page1 Page2 Next-> Last->> and each button works. The pagenum is sent through ajax and reloads…
Sweepster
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Java generate random numbers using Possion/Gaussian/Exponential/Geometric/Uniform distribution

How can I generate a random number in Java using different distributions within a range(0-99). I know the standard Java.util.Random getNextInt() uses Uniform and PRNG. How would I use nextGaussian? But how would I generate the rest? The problem is…
kal
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Adding a trendline in basic R code (no GGPlot) for multiple plot graph of exponential and 2 factor polynomial curves

I am trying to add trendlines to a multi-plot graph using basic R code. Could use some help to to add trendlines for non-linear functions, and am not sure if this is possible with basic R. I may need to upgrade my skillset to ggplot and thought I…
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How to get (-8)^0.333333 = -2 in MATLAB?

Using MATLAB exponential function: (-8)^0.333333 ans = 1.0000 + 1.7320i How to get (-8)^0.333333 = -2 instead? x=-10:-1; x.^0.333333 How to get real value? How to redefine ^: x.^y to sign(x).*abs(x.^y))
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I can't fit an exponential function in a data set

I have a data set from a laboratory that I did in which I studied the characteristics of current and voltage in a solar panel. The data is a bit inconsistent but it is visible that it is an exponential function. I need to determine the exponential…
Ghidic Vladislav
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Avoiding NaN and Inf when computing exponential in Matlab

Suppose I have a vector S and am interested in computing the value ln(1+exp(S)) or ln(1+exp(-S)). However, if an entry is too large or too small, I will encounter Inf problems or other numerical issues. One solution is to notice that…
Kilkik
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How to show standard error with curve_fit from scipy in python?

I am trying to fit multiple curve equations to my data to determine what kind of decay curve best represents my data. I am using the curve_fit function within scipy in python. Here is my example data: data = {'X':[1, 2, 3, 4, 5, 6, 7, 8, 9, 10,…
LostinSpatialAnalysis
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