Questions tagged [decomposition]

Decomposition might refer to Time Series Decomposition. Decomposing a time-series into Seasonal and Trend components can be achieved by using several methods, such as STL (which uses a Loess smoothing algorithm).

Prefer using if applicable.


Time series data can exhibit a variety of patterns, and it is often helpful to split a time series into several components, each representing an underlying pattern category.

There are three types of time series patterns: trend, seasonality and cycles. When we decompose a time series into components, we usually combine the trend and cycle into a single trend-cycle component (often just called the trend for simplicity). Thus we can think of a time series as comprising three components: a trend-cycle component, a seasonal component, and a remainder component (containing anything else in the time series). For some time series (e.g., those that are observed at least daily), there can be more than one seasonal component, corresponding to the different seasonal periods.

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PHP String Decomposition

What is the best way to decompose the following string: $str = '/input-180x129.png' Into the following: $array = array( 'name' => 'input', 'width' => 180, 'height' => 129, 'format' => 'png', );
Dragos Rizescu
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LU decomposition for tridiagonal matrices (Java)

I'm creating a class to represent tridiagonal matrices. These are square matrices which have a set of non-zero values on the diagonal, and non-zero values on the upper and lower diagonals and then zeros everywhere else. To store them, I'm using…
Jarred Morris
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Enhancing testability by decomposing batch tasks

I can't seem to find much information on this so I thought I'd bring it up here. One of the issues I often find myself running into is unit testing the creation of a single object while processing a list. For example, I'd have a method signature…
gcso
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Minimum Weight Triangulation Dynamic Programming Algorithm

So, I'm trying to understand the dynamic programming algorithm for finding the minimum weighted triangulation decomposition of a convex polygon. For those of you that don't know, triangulation is where we take a convex polygon, and break it up into…
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best method of turning millions of x,y,z positions of particles into visualisation

I'm interested in different algorithms people use to visualise millions of particles in a box. I know you can use Cloud-In-Cell, adaptive mesh, Kernel smoothing, nearest grid point methods etc to reduce the load in memory but there is very little…
Griff
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How to accurately decompose positive semidefinite matrix and use the lower triangular part in linear equations

I have n arbitrary p x 1 vectors x_i, and p x k matrices A_i, and n p x p positive semidefinite matrices S_i, where some (often most) of the *S_i*'s are same (for example only two different S matrices, one positive definite which applies to…
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[a b]=cholcov function returns a=[] and b=NaN for a symmetric positive definite matrix

I have this matrix: S= 6.84370358358718e-006 -7.45833473076585e-007 -7.45833473076565e-007 7.11723106043725e-006 It is symmetric: S-S'= 0 -2.00111533788828e-020 2.00111533788828e-020 …
Ramin
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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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Adding a minimal key to a BCNF decomposition

If I will add a minimal key to a given BCNF decomposition can it be no more a BCNF decomposition? Formally, say I have F (group of functional dependencies), schema R and it's BCNF decomposition {R1,R2,R3,R4} and I will add another group R5 to the…
user550413
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LU decomposition using ejml

I'm trying to use ejml library to make LU decomposition of a matrix. All goes well for the calculation of the SVD decomposition, for LU decomposition I don't know to use ejml library. I would like your help import java.util.Scanner; import…
whiteTIGER
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What are database schema decompositions and why do we need them?

What is database schema decomposition? Why do we need decompositions?
Md Nasir Uddin
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Multiresolutional wavelet decomposition code

I am not an advanced mathematical, so I understand only the basics of wavelet decomposition. I found JWave, which is a Java implementation of wavelet processing. The author tells me it can by its nature to multidimensional decomposition. The problem…
IamIC
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Polygon triangulation

I am working on nesting of sheet metal parts and am implementing Minkowski Sums to find No Fit Polygons for nesting. The problem is I can give only convex sets as input to the code which calculates Minkowski sums for me. Hence I need to break a…
Saurabh
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How to cut a concave polyhedron A, using a convex polyhedron B whose vertex set is a subset of B?

I am working on polyhedron convex decomposition. I try to use a limited plane to cut my polyhedron. The way I thought of is to construct a convex polyhedron along the limited plane normal vector. However, i meet some trouble. My plan is below. I…
Mengyu Chen
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I was trying to see the seasonal and trend factor in the timeseries, but graph is not working correctly. Tried after deleting cache memory too

Hi was trying to do seasonal_decomposition for a time series, but wasn't getting proper result: date value 2020-02-01 67.05 2020-03-01 69.08 2020-06-01 70.25 2020-07-01 68.74 2020-08-01 67.31 . . . till 2022-11-04 Code: from…
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