apache-commons-math

问题 The org.apache.commons.math3.optim.linear package in Apache Commons Math Library allows Linear Optimization but the returned values are double. Is there any way to perform Integer Linear Programming using this library? I tried googling but there seems to be no mention of ILP anywhere. Alternatively, is there any other Java library that can do ILP? please not that I need to run this on android so SCPSolver, GLPK, Or-tools. etc. are not possible. Thanks in advance. 回答1: As this question and

问题 I made a test program to try the NewtonRaphsonSolver class through the Apache Commons Math library. Newton's method is used to find roots for a given function. The test program that I wrote references the cos(x) function (I have a more difficult function to analyze and am looking at the cos(x) function first). The code for the test program is import org.apache.commons.math3.analysis.differentiation.DerivativeStructure; import org.apache.commons.math3.analysis.differentiation

问题 How can I multiply a given RealVector by a RealMatrix ? I can't find any "multiply" method on both classes, only preMultiply but it seems not work: // point to translate final RealVector p = MatrixUtils.createRealVector(new double[] { 3, 4, 5, 1 }); // translation matrix (6, 7, 8) final RealMatrix m = MatrixUtils.createRealMatrix(new double[][] { {1, 0, 0, 6}, {0, 1, 0, 7}, {0, 0, 1, 8}, {0, 0, 0, 1} }); // p2 = m x p final RealVector p2 = m.preMultiply(p); // prints {3; 4; 5; 87} // expected

问题 How can I multiply a given RealVector by a RealMatrix ? I can't find any "multiply" method on both classes, only preMultiply but it seems not work: // point to translate final RealVector p = MatrixUtils.createRealVector(new double[] { 3, 4, 5, 1 }); // translation matrix (6, 7, 8) final RealMatrix m = MatrixUtils.createRealMatrix(new double[][] { {1, 0, 0, 6}, {0, 1, 0, 7}, {0, 0, 1, 8}, {0, 0, 0, 1} }); // p2 = m x p final RealVector p2 = m.preMultiply(p); // prints {3; 4; 5; 87} // expected

问题 I'm trying to implement some Interpolation functions to plot some values where the X value = Date.seconds and the Y value = double. I'v been researching using the Apache Commons Math lib to achieve this and I've found a method I think I might be able to use here The method I'm trying to understand: public double linearInterp(double[] x, double[] y, double xi) { // return linear interpolation of (x,y) on xi LinearInterpolator li = new LinearInterpolator(); PolynomialSplineFunction psf = li

问题 I am comparing two linear models in R with Anova, and I would like to do the same thing in Java. To simplify it, I took the example code from https://stats.stackexchange.com/questions/48854/why-am-i-getting-different-intercept-values-in-r-and-java-for-simple-linear-regr and modified it a bit below. The models are test_trait ~ geno_A + geno_B and test_trait ~ geno_A + geno_B + geno_A:geno_B . The coefficients of the models implemented in R and Java are the same. In R I use anova(fit, fit2)

问题 Apache Math 3.4 (and 3.3), java 1.8.0_25 import org.apache.commons.math3.distribution.ChiSquaredDistribution; ChiSquaredDistribution chisq = new ChiSquaredDistribution(23) System.out.println(1.0 - chisq.cumulativeProbability(130) // 1.1102230246251565E-16 System.out.println(1.0 - chisq.cumulativeProbability(131) // 0.0 Why does Apache Math return 0.0 in the second call? Some stat libraries (Excel, but not R) do return values that are much smaller than 1E-16 for the tail probabilities.

问题 So I've been looking for a while, and found that I need to import the org.apache.commons.math3.util.ArithmeticUtils library in a Java program I'm writing. Now this is my first Java program, and I can't figure out how to use the library. Am I missing something here? Do I need to attach an option when I'm using the command? javac MyProgramNameGoesHere.java -something(?) Or is there some special place where I need to install the the library package to? Edit:: I am also doing this with gEdit and

问题 I am trying to integrate a very simple function. integral(x.dx). Instead of getting an answer of 1, I am getting an answer as 0, or 0.5 when I include limits from 0 to 1. Is there something I misunderstand about the implementation of the integration in apache commons library? import org.apache.commons.math3.analysis.integration.*; import org.apache.commons.math3.analysis.polynomials.*; public static void main(String args[]) { SimpsonIntegrator simpson = new SimpsonIntegrator();

问题 I am computing the SD of a vector using Apache Commons Math. The problem: I get different values than by hand DescriptiveStatistics stats = new DescriptiveStatistics(); stats.addValue(value1); ... stats.addValue(value8); stats.getStandardDeviation(); E.g., take the values [1699.0, 1819.0, 1699.0, 1719.0, 1689.0, 1709.0, 1819.0, 1689.0]. SD should be 52.067 but Commons Math = 55.662. What am I doing wrong? 回答1: The Apache StandardDeviation class can be used for computing both values: "Standard