python - LU decomposition with pivoting in numpy -


i can't find what's wrong attempt @ implementing lu decomposition partial pivoting pseudo-code here (page 6). code pasted below. can spot problem?

def lupdecomposition(matrix): n, m = matrix.shape assert n == m, "lu decomposition applicable square matrices" l = np.identity(n) u = matrix.copy() p = np.identity(n)  k in range(n-1):      # pivoting: index of maximum in k-th column on diagonal or below     index = np.argmax(abs(u[k:,k]))     index += k      # pivoting: permute rows     if index != k:         u[[index,k],k:n] = u[[k,index],k:n]         p[[index,k]] = p[[k,index]]         if index > 0:             l[[index,k],0:(k-1)] = l[[k,index],0:(k-1)]      # calculating next column in l , modifing rows in u     j in range(k+1,n):         l[j,k] = u[j,k] / u[k,k]         u[j,k:] -= l[j,k]*u[k,k:]  return l,u,p


-

Comments

Post a Comment

Popular posts from this blog

css - SVG using textPath a symbol not rendering in Firefox -

using textpath within symbol doesn't render in firefox. renders fine in latest chrome , ie, when try reference symbol, svg text doesn't render in firefox (37.0.1) - first box appears empty. code below (no external dependencies), there should 2 boxes word test flowing vertically in centre of each. edit: thought issue somehow involved flexbox layout, until paul pointed out issue exists without flexbox layout. the html is: <div> <svg id="not_working" viewbox="0 0 250 1200" preserveaspectratio="xmidymid meet"> <symbol id="test_symbol1" preserveaspectratio="xmidymid meet" viewbox="0 0 250 1200"> <path id="test_symbol_path" d="m 100 1200 l 100 0" /> <text font-size="100" fill="red"> <textpath text-anchor="middle" startoffset="50%" xlink:href="#test_symbol_path...
Read more

Java 8 + Maven Javadoc plugin: Error fetching URL -

i attempting generate javadoc links javadoc dependencies. have tried various means generate javadoc not produce qualified class names references classes dependencies. wanted links java doc simplified class names. however, java api classnames, no links , have qualified class names. working java 8. have following configuration: <plugin> <groupid>org.apache.maven.plugins</groupid> <artifactid>maven-javadoc-plugin</artifactid> <version>2.10.2</version> <configuration> <reportoutputdirectory>${project.basedir}/target</reportoutputdirectory> <destdir>javadoc</destdir> <windowtitle>epiphany</windowtitle> <doctitle>epiphany</doctitle> <show>private</show> <detectlinks>false</detectlinks> <detectoffline...
Read more

datatable - Matlab struct computations -

i download data yahoo! finance with: data = getyahoodailydata({'msft', 'axp'},'01/01/2000', '01/01/2015', 'dd/mm/yyyy'); and data stored 1x1 struct. want create tx2 matrix of daily adjusted closing prices msft , axp, column 7 in each table in struct. how can that? or better : there way make computations directly on information/prices in struct? you can access data in struct name. vecmsftadj = data.msft.adjclose; vecaxpadj = data.axp.adjclose; % if want n x 2 matrix madjclose = [vecmsftadj, vecaxpadj]; % personnaly prefer working table tadjclose = table; tadjclose.msftadj = vecmsftadj; tadjclose.axpadj = vecaxpadj;
Read more