Posts Tagged ‘ graphics ’

Example 7.4: A prettier jittered scatterplot

July 2, 2009
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Example 7.4: A prettier jittered scatterplot

The plot in section 7.3 has some problems. At the very least, the jittered values ought to be between 0 and 1, so the smoothed lines fit better with them. Once again we use the data generated in section 7.2 as an example. For both SAS and R, we use conditioning (section 1.11.2) to make the jitter happen...

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How to plot a graph in R

June 2, 2009
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How to plot a graph in R

Here's a quick tutorial on how to get a nice looking graph out of R (aka the R Project for Statistical Computing). Don't forget that help for any R command can be displayed by typing the question mark followed by the command. For example, to see help o...

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Identify Data Points in Off-Screen R Graphics Devices

March 16, 2009
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Today Ruya Gokhan Kocer asked me how to use the R function identify() in off-screen graphics devices. Actually it’s pretty easy as long as we obtain the list returned by identify(pos = TRUE). For example, # open a windows device x11() x = rnorm(20) y = rnorm(20) plot(x, y) # identify 5 points id = identify(x, y, n = 5, pos =

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Andrews’ Curve And Parallel Coordinate Graph

March 11, 2009
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Unison graph and parallel coordinate graph share similar thought in visualising the difference of multidimensional data, thought the former is much more complicated. Based on iris data, we can see their performance.Parallel coordinate graphAndrews' Cur...

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Scatterplots

March 11, 2009
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There are many types of scatterplots in R, here are some examples based on the famous Iris data.pairs() and coplot() in package graphics.gpairs() in package YaleToolkit.scatterplot.matrix() or spm() in package car.splom() in package lattice.

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Illinois long-term selection experiment for oil and protein in corn

February 22, 2009
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Illinois long-term selection experiment for oil and protein in corn

Researchers at the University of Illinois are conducting one of the longest experiments in biology - Illinois long-term selection experiment for oil and protein in corn. The experiment started in 1896 and is still active! In esence they are selecting l...

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R: Good practice – adding footnotes to graphics

February 17, 2009
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R: Good practice – adding footnotes to graphics

In some statistical programs there is the option available to attach a footnote to the graphical output that is created. This footnote may contain the name of the script or the file that produced the graphic, the author’s name and the date of creation. In SAS for example there is a footnote command to achieve

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Plot symbols in R

November 18, 2008
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In the plot environment, the "pch" parameter decides the symbol of your output. There are about 130 symbols hard coded and passed into "pch."However, there are still some symbols that are not in these 130 pch's. For instance, there is no checkmark. To plot checkmark or other symbols, we can use symbol() in the expression()...

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Plotting Math in R

October 29, 2008
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Plotting math in R can be acheived using the expression(). To know detailed usage, in R console,demo(plotmath)But expression() is not flexible when you want to plot math symbols and parameters altogether. In this case, we use bquote() which is actually a wraper for substitute() and quote(). It has the ability to do paste() and expression() altogether. Here...

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