EVOLUTION-MANAGER

Edit File: wtdensity.cpp

// -*- mode: C++; c-indent-level: 4; c-basic-offset: 4; tab-width: 8; -*- // // Wt usage example for RInside, inspired by the standard 'density sliders' example // // Copyright (C) 2011 Dirk Eddelbuettel and Romain Francois // // This file is licensed under GPL 2 or later, as are the rest of RInside and Rcpp // // Derived from hello.C in the Wt sources // Copyright (C) 2008 Emweb bvba, Heverlee, Belgium. #include <cstdio> #include <Wt/WApplication> #include <Wt/WBreak> #include <Wt/WContainerWidget> #include <Wt/WLineEdit> #include <Wt/WPushButton> #include <Wt/WText> #include <Wt/WImage> #include <Wt/WSpinBox> #include <Wt/WGroupBox> #include <Wt/WButtonGroup> #include <Wt/WRadioButton> #include <Wt/WHBoxLayout> #include <Wt/WEnvironment> #include <Wt/WFileResource> #include <RInside.h> using namespace Wt; class DensityApp : public WApplication { public: DensityApp(const WEnvironment& env, RInside & R); private: WLineEdit *codeEdit_; // to edit the RNG draw expression WButtonGroup *group_; // holds the radiobuttons WSpinBox *spin_; // selects the density bandwidth WImage *img_; // displays the image WFileResource *imgfile_; // controls the file resources WText *greeting_; // text label for status message void reportButton(); // called when new button selected void reportEdit(); // called when RNG expression edited void reportSpinner(); // called when bandwidth changed void plot(); // to call R for new plot enum Kernel { Gaussian = 0, Epanechnikov = 1, Rectangular = 2, Triangular = 3, Cosine = 4 }; RInside & R_; // reference to embedded R instance std::string tempfile_; // name of file used by R for plots int bw_, kernel_; // parameters used to estimate the density std::string cmd_; // random draw command string Rcpp::NumericVector Yvec_; // the random draw }; // The env argument contains information about the new session, and the initial request. // It must be passed to the WApplication // constructor so it is typically also an argument // for your custom application constructor. DensityApp::DensityApp(const WEnvironment& env, RInside & R) : WApplication(env), R_(R) { setTitle("Witty WebApp With RInside"); // application title setCssTheme("polished"); messageResourceBundle().use(appRoot() + "wtdensity"); new WText(WString::tr("overview"), root()); std::string tfcmd = "tfile <- tempfile(pattern=\"img\", tmpdir=\"/tmp\", fileext=\".png\")"; tempfile_ = Rcpp::as<std::string>(R_.parseEval(tfcmd)); // assign to 'tfile' in R, and report back bw_ = 100; kernel_ = 0; // parameters used to estimate the density cmd_ = "c(rnorm(100,0,1), rnorm(50,5,1))"; // random draw command string new WText(WString::tr("user input"), root()); Wt::WContainerWidget *wc = new Wt::WContainerWidget(root()); wc->setStyleClass("box"); Wt::WHBoxLayout *layout = new Wt::WHBoxLayout(); Wt::WContainerWidget *midbox = new Wt::WContainerWidget(root()); layout->addWidget(midbox); Wt::WContainerWidget *container = new Wt::WContainerWidget(root()); layout->addWidget(container); wc->setLayout(layout, AlignTop | AlignJustify); midbox->addWidget(new WText("Density estimation scale factor (div. by 100)")); midbox->addWidget(new WBreak()); // insert a line break spin_ = new WSpinBox(midbox); spin_->setRange(5, 200); spin_->setValue(bw_); spin_->valueChanged().connect(this, &DensityApp::reportSpinner); midbox->addWidget(new WBreak()); // insert a line break midbox->addWidget(new WText("R Command for data generation")); // show some text midbox->addWidget(new WBreak()); // insert a line break codeEdit_ = new WLineEdit(midbox); // allow text input codeEdit_->setTextSize(30); codeEdit_->setText(cmd_); codeEdit_->setFocus(); // give focus codeEdit_->enterPressed().connect(this, &DensityApp::reportEdit); group_ = new Wt::WButtonGroup(container); // use button group to arrange radio buttons Wt::WRadioButton *button; button = new Wt::WRadioButton("Gaussian", container); new Wt::WBreak(container); group_->addButton(button, Gaussian); button = new Wt::WRadioButton("Epanechnikov", container); new Wt::WBreak(container); group_->addButton(button, Epanechnikov); button = new Wt::WRadioButton("Rectangular", container); new Wt::WBreak(container); group_->addButton(button, Rectangular); button = new Wt::WRadioButton("Triangular", container); new Wt::WBreak(container); group_->addButton(button, Triangular); button = new Wt::WRadioButton("Cosine", container); new Wt::WBreak(container); group_->addButton(button, Cosine); group_->setCheckedButton(group_->button(kernel_)); group_->checkedChanged().connect(this, &DensityApp::reportButton); new WText(WString::tr("r result"), root()); Wt::WContainerWidget *botbox = new Wt::WContainerWidget(root()); botbox->setStyleClass("box"); imgfile_ = new Wt::WFileResource("image/png", tempfile_); imgfile_->suggestFileName("density.png"); // name the clients sees of datafile img_ = new Wt::WImage(imgfile_, "PNG version", botbox); new WText(WString::tr("browser info"), root()); Wt::WContainerWidget *stbox = new Wt::WContainerWidget(root()); stbox->setStyleClass("box"); greeting_ = new WText(stbox); // empty text greeting_->setText("Setting up..."); useStyleSheet("wtdensity.css"); // set our style sheet last reportEdit(); // create a new RNG draw in Yvec_ plot(); // and draw a new density plot } void DensityApp::reportButton() { kernel_ = group_->checkedId(); // get id of selected kernel plot(); } void DensityApp::reportEdit() { cmd_ = codeEdit_->text().toUTF8(); // get text written in box, as UTF-8, assigned to string std::string rng = "y2 <- " + cmd_ + "; y <- y2"; R_.parseEvalQNT(rng); // evaluates expression, assigns to 'y' Yvec_ = R_["y"]; // cache the y vector plot(); } void DensityApp::reportSpinner() { bw_ = spin_->value(); // get the value of the spin selector plot(); } void DensityApp::plot() { const char *kernelstr[] = { "gaussian", "epanechnikov", "rectangular", "triangular", "cosine" }; greeting_->setText("Starting R call"); R_["tfile"] = tempfile_; R_["bw"] = bw_; R_["kernel"] = kernelstr[kernel_]; // passes the string to R R_["y"] = Yvec_; std::string cmd0 = "png(filename=tfile,width=600,height=400); plot(density(y, bw=bw/100, kernel=kernel), xlim=range(y)+c(-2,2), main=\"Kernel: "; std::string cmd1 = "\"); points(y, rep(0, length(y)), pch=16, col=rgb(0,0,0,1/4)); dev.off()"; std::string cmd = cmd0 + kernelstr[kernel_] + cmd1; // stick the selected kernel in the middle R_.parseEvalQ(cmd); // evaluate command -- generates new density plot imgfile_->setChanged(); // important: tells consumer that image has changed, forces refresh greeting_->setText("Finished request from " + this->environment().clientAddress() + " using " + this->environment().userAgent()) ; } WApplication *createApplication(const WEnvironment& env) { // You could read information from the environment to decide whether // the user has permission to start a new application // // We grab an instance of the embedded R. Note we can start only one, // so resource conflicts have to be managed (eg add mutexes etc) // return new DensityApp(env, RInside::instance()); } int main(int argc, char **argv) { RInside R(argc, argv); // create the one embedded R instance // Your main method may set up some shared resources, but should then // start the server application (FastCGI or httpd) that starts listening // for requests, and handles all of the application life cycles. // // The last argument to WRun specifies the function that will instantiate // new application objects. That function is executed when a new user surfs // to the Wt application, and after the library has negotiated browser // support. The function should return a newly instantiated application // object. return WRun(argc, argv, createApplication); }