Inclass examples with r code response surface analysis rsm stat 579 university of new mexico erik b. Then plot them as a surface and display a contour plot under the surface plot. You can easily draw these as a scatter plot, but for a large number of points, some sort of density or contour plot is called for. Contour line is the most common usage in cartography, but isobath for underwater depths on bathymetric maps and isohypse for elevations are also used. Density profiles and contour plots university of warwick. I want to get contour and perspective plots for rsm object for each level of a factor here for block. You may get two contours from one click like those with the same response value. Contourplot initially evaluates f at a grid of equally spaced sample points specified by plotpoints. A contour plot is a graphical technique for representing a 3dimensional surface by plotting constant z slices, called contours, on a 2dimensional format. Contour plots are useful for establishing the response values and operating conditions as required. Design expert practice design of experiment v 9 statistical analysis of data response surface method rsm three factors three levels full factorial.
Flowjo draws only one type of contour plot, using equal probability contouring. A surface plot is a threedimensional surface that has solid edge colors and solid face colors. Perhaps the most straightforward way to prepare such data is to use the np. Either type of contour data can be plotted on linear or log axes. A contour plot is constructed based on equation of response, a simple method to interprete this plot by adding contour line thus it. You can interact with the contour plot just like any other excel plot. In determining how to color regions between contour levels, contourplot looks first at any explicit setting given for contourshading, then at the setting for colorfunction. This algorithm generates, in general, graphs which are most accurately interpreted by our brains, in terms of relative frequencies of subpopulations. Inclass examples with r code response surface analysis. We also chose to move the legend in the area of extrapolation. Contour10 specifies that the plot will divide the values of z into ten increments, and each increment will have a different plotting symbol. Inclass examples with r code response surface analysis rsm.
Primitive class for the contour plot graphics type. Draws contour lines in the userdefined color and at the userdefined levels. Contour plots can be made using either matrix data or xyz triplets. A contour plot provides a 2dimensional view of the surface where points that have the same response are connected to produce contour lines of constant responses. Using 2d contour plots within ggplot2 to visualize. Rather than showing the individual data points, surface plots show a functional relationship between a designated dependent variable y, and two independent variables x and z. Suppose you have a list of points, for example x,y pairs. Contour plots are useful for establishing the response values and operating conditions that you want. Then drag the contour around it will become highlighted. A 3d surface plot displays a 3dimensional view of the surface. How to interpret the contourplot from response surface. Lenth the university of iowa abstract this introduction to the r package rsm is a modi ed version oflenth2009, pub. Output minimum working example libraryrsm cr contourisolineplots contour pseudocolor mesh surf surfc filledcontour contour3 stem3 bar3 figure4. Contour plots are useful for investigating desirable response values and operating conditions.
Jul 05, 2017 design expert practice design of experiment v 9 statistical analysis of data response surface method rsm three factors three levels full factorial. This example shows how to change the colors used in a filled contour plot. The x and y values represent positions on the plot, and the z values will be represented by the contour levels. The plot request plots y on the vertical axis, plots x on the horizontal axis, and specifies z as the contour variable. The methods for positioning the labels on contours are simple draw at the edge of the plot, overlaying the contour line, edge draw at the edge of the plot, embedded in the contour line, with no labels overlapping and flattest draw on the flattest section of the contour, embedded in the contour line, with no labels overlapping. Use a contour plot to see how a response variable relates to two predictor variables. In the vacant region of the ab contour plot rightclick and select add contour. In cartography, the contour interval is the elevation difference between adjacent contour lines. Responsesurface methods in r, using rsm updated to version 2. You can create a contour plot with emphasis on selected contour lines by splitting the data and creating two overlapping contour plots. A contour plot provides a twodimensional view in which all points that have the same response are connected to produce contour lines of constant responses. An rsm object is an extension of a lm object with extra responsesurfacerelated information included. The rstride and cstride kwargs set the stride used to sample the input data to generate the graph.
Mar 18, 2008 plenty of packages allow you to plot contours of a z value. Output minimum working example library rsm cr plot with a contour plot underneath. Design expert practice design of experiment v 9 example. For example, if the predictor variables are x1, x2, and x3, the contour plot of x2 versus x1 would be based on the fitted surface sliced at the x3 value specified in at.
The stride arguments are only used by default if in the classic mode. Jul 24, 2016 we use the contour function in base r to produce contour plots that are wellsuited for initial investigations into three dimensional data. Contour plots portray data for three variables in two dimensions. A key showing how the colors map to z values is shown to the right of the plot. How to read contour plots in response surface methodology.
Contours of matrix data can be plotted using nonlinear usersupplied spacing. The contour interval should be the same over a single map. We then develop visualizations using ggplot2 to gain continue reading using 2d contour plots within ggplot2 to visualize relationships between three variables. Contourisolineplots contour pseudocolor mesh surf surfc filledcontour. Matlab automatically selects the contour lines to display. Contour plot with contour lines colored using a continuous outcome variable qsec instead of coloring the whole plot, it may be more desirable to color just the contour lines of the plot.
Creating and intepreting contour plots using dasp and gnuplot bob baulch and karl shutes 1 october, 2008 summary this notes describes how contour plots, which are two dimensional representations of welfare distributions that can be regarded as a continuous analogue to transition matrices, can be creating. It is obtained by plotting two independent variables on the x and yscales, and the response z. Contour plots and color mapping part 1 create contour plot from a matrix duration. Density and contour plots python data science handbook. This function produces a contour plot with the areas between the contours filled in solid color cleveland calls this a level plot. Interpret the key results for contour plot minitab. Technologyenabling science of the computational universe.
That is, given a value for z, lines are drawn for connecting the x,y coordinates where that z value occurs. How to interpret the contourplot from response surface methodology. Optional named list of fixed values to use for surface slices. If either is 0 the input data in not sampled along this direction producing a 3d line plot rather than a wireframe plot. An alternative method to representing multivariable functions with a twodimensional input and a onedimensional output, contour maps involve drawing purely in the input space. Each contour line is shown in an xy plot and has a constant value on a third variable. It includes a data generator for polynomials or any equation. All contouring algorithms have advantages and disadvantages, but probability contouring is probably the most. Output minimum working example libraryrsm cr contour plot of x2 versus x1 would be based on the fitted surface sliced at the x3 value specified in at. The column and row indices of z are the x and y coordinates in the plane, respectively. It accommodates rectangular data, nearly rectangular data, and irregular data.