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Questions tagged [singular]

Singularity is a mathematical term indicating an undefined point on a set (function). Singularity arises in many mathematical optimization problems with many variables.

An example of singularity is the derivative of the absolute value function |x| at x = 0.

Singularity arises in many ill-posed problems

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Matlab - generate random nonsingular triangular matrix

How can I generate a random triangular matrix? (upper and lower) Usually I use rand(n) but if I try tril(rand(n)) it will be singular and I don't want that.
Giuseppe Trapasso
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unspecified minpoly in singular

I am learning using singular , and I run the following script in singular ring A1=(2^3,a),x,dp; minpoly ; 1*a^3+1*a^1+1*a^0 I am confused by it, I have not specified a monopoly for A1 rings, but the A1 have a monopoly already. Does this…
沈胜宇
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Square Root of a Singular Matrix in R

I need to compute the matrix A on the power of -1/2, which basically means the square root of the initial matrix's inverse. If A is singular then the Moore-Penrose generalized inverse is computed with the ginv function from the MASS package,…
GyD
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Java library to find parametric solutions to a linear algebra system with singular matrix

I would like to solve in Java this integer linear algebra problem, where xi, yi, zi are the integer variables (all positive, xi≥0, yi≥0, zi≥0), and a, b, c, d, e, f, g, h are the constants (positive integers ≥0, for example a=20, b=12, c=28, d=24,…
madx
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Lapack routine dgesv mlogit mlogit in R

I am getting an error in R when I try to run mlogit. I try to estimate the following: logit3 <- mlogit(choice~1|prod1+prod2+camp1+camp2+salm1+salm2+orig1+orig2+price1+price2, data=CNLdata) and the error appeared is the following: logit3 <- …
Yannis
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How to get the return value if an R function has an error

I want to test if a matrix is singular or not in R. I tried a function, which is is.non.singular.matrix() in matrixcalc package. However, sometimes, in my case there is a 60*60 matrix generated, the function returns FALSE, which means the matrix is…
Jiang Du
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How to compute the inverse of a close to singular matrix in R?

I want to minimize function FlogV (working with a multinormal distribution, Z is data matrix NxC; SIGMA it´s a square matrix CxC of var-covariance of data, R a vector with length C) FLogV <- function(P){ (here I define parameters, P, within R and…
Maria D
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Are Rails 4 path_helpers broken with singular resources?

I am using Rails 4.0.0 with Mongoid and HAML I have the following model structure: class Merchant has_one :setting end class Setting belongs_to :merchant has_many :categories end class Category belongs_to :setting end Setting is layed out…
GeorgieF
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Sparse Matrix Editing

I'm new here so I'm not sure if it's asked before, but I did look out to see if it's there. I'm interested if anyone has encountered similar problem. I have sparse matrix that is being LU decomposed and than those L and U factors are than inverted.…
Aranđel Šarenac
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Q job unsuccessful mahout ssvd

I'm trying to run ssvd on some tfidf-vectors in mahout. When I run it in Java code as follows (with mahout 0.6 jars), it works fine: public static void main(String[] args){ runSSVDOnSparseVectors(vectorOutputPath +…
Matthew Saltz
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MATLAB Integration Situation

I want to evaluate the integral of this function : (cos(t^2)*sin(t)^2)^(1/2) over the period -15*pi:50*pi I am using these : f=@(t) (cos(t.^2).*sin(t).^2).^(1/2); quad(f,-15*pi,50*pi) But i am getting warned: Warning: Maximum function count…
Murat Şeker
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Computationally singular matrix inverse error?

This error comes up when I am dividing by the matrix inverse. Error in solve.default(x) : system is computationally singular: reciprocal condition number = 6.85861e-18 ``` What are the ways to solve this? I am using the matrix.inverse function…
Jason_Leto
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Python- trying to understand plural vs singular in code. For example: for i, square in enumerate(squares):

I'm trying to clarify my understanding regarding situations in the code in which the singular seems to extract from the plural. I'm not sure if this is standard among different languages, or, unique to specific situations in python. Regardless, in…
Foreverlearning
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Php mysql search - Search not working if with plural and singular

If I search "sales order" it's fetching "sales order" and "sales orders" in results. It's fetching the result with "s" also. But if I search "sales orders" it's fetching "sales orders" only but I want "sales order" will also fetch. I am using php…
ANkit Joshi
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singular plural depending on state

I'm using the script MixItUp for filtering and sorting nodes in xml files. I have a script for counting the nodes which changes upon filtering - and the count changes as it should. What the script (read: I) don't accomplish is the correct singular…
McClaudLive
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