inverse

问题 To plot a normal distribution curve in R we can use: (x = seq(-4,4, length=100)) y = dnorm(x) plot(x, y) If dnorm calculates y as a function of x, does R have a function that calculates x as a function of y? If not what is the best way to approach this? 回答1: I'm not sure if the inverse of the density function is built in -- it's not used nearly as often as the inverse of the cumulative distribution function. I can't think offhand of too many situation where the inverse density function is

问题 The following code shows a problem of singularity of a matrix, since working in Pycharm I get raise LinAlgError("Singular matrix") numpy.linalg.linalg.LinAlgError: Singular matrix I guess the problem is K but I cannot understand exactly how: from numpy import zeros from numpy.linalg import linalg import math def getA(kappa): matrix = zeros((n, n), float) for i in range(n): for j in range(n): matrix[i][j] = 2*math.cos((2*math.pi/n)*(abs(j-i))*kappa) return matrix def getF(csi, a): csiInv =

问题 I've used random.normal() in the past to generate a single number who, if called multiple times, in aggregate would create a bell curve distribution. What I'm trying to do now is to create the opposite / inverse, where the distribution is biased towards the extremes within a range? There are built in functions in excel that seem to do what I want. Is there a way to do it in python? Thank you 回答1: It appears you want a distribution with an "upside-down bell curve" compared to the normal

问题 I've used random.normal() in the past to generate a single number who, if called multiple times, in aggregate would create a bell curve distribution. What I'm trying to do now is to create the opposite / inverse, where the distribution is biased towards the extremes within a range? There are built in functions in excel that seem to do what I want. Is there a way to do it in python? Thank you 回答1: It appears you want a distribution with an "upside-down bell curve" compared to the normal

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 6 days ago . Improve this question Can you help me in finding values of A and B in : −29≡A−29≡B(mod 52 ) I tried many times but I got the wrong answer. Hard time finding exactly the correct answer. 来源： https://stackoverflow.com/questions/63401142/a-simple-help-would-be-appreciated

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 6 days ago . Improve this question Can you help me in finding values of A and B in : −29≡A−29≡B(mod 52 ) I tried many times but I got the wrong answer. Hard time finding exactly the correct answer. 来源： https://stackoverflow.com/questions/63401142/a-simple-help-would-be-appreciated

问题 I am using SciPy's boxcox function to perform a Box-Cox transformation on a continuous variable. from scipy.stats import boxcox import numpy as np y = np.random.random(100) y_box, lambda_ = ss.boxcox(y + 1) # Add 1 to be able to transform 0 values Then, I fit a statistical model to predict the values of this Box-Cox transformed variable. The model predictions are in the Box-Cox scale and I want to transform them to the original scale of the variable. from sklearn.ensemble import

问题 I want to determine (in c++) if one float number is the multiplicative inverse of another float number. The problem is that i have to use a third variable to do it. For instance this code: float x=5,y=0.2; if(x==(1/y)) cout<<"They are the multiplicative inverse of eachother"<<endl; else cout<<"They are NOT the multiplicative inverse of eachother"<<endl; will output: "they are not..." which is wrong and this code: float x=5,y=0.2,z; z=1/y; if(x==z) cout<<"They are the multiplicative inverse of

问题 Is there a way to express the inverse of any function in Scala? For example if I have a function f like this: (x: Int) => x + 1 I would like to be able write an inverse function g like: (f(x): Int) => x // not a valid scala syntax or (x: Int) => inverse(f(x)) // inverse would return (x => x -1) Do you know a way to do this kind of thing in Scala? N.B: x => x+1 is just for the example. I'm looking for a generic way to solve this kind of task. 回答1: No, something like that is not possible. The

问题 Let's say I have a regular expression that works correctly to find all of the URLs in a text file: (http://)([a-zA-Z0-9\/\.])* If what I want is not the URLs but the inverse - all other text except the URLs - is there an easy modification to make to get this? 回答1: If for some reason you need a regex-only solution, try this: ((?<=http://[a-zA-Z0-9\/\.#?/%]+(?=[^a-zA-Z0-9\/\.#?/%]))|\A(?!http://[a-zA-Z0-9\/\.#?/%])).+?((?=http://[a-zA-Z0-9\/\.#?/%])|\Z) I expanded the set of of URL characters a