z is a real matrix of size (n1,n2), containing the values of the function or a Scilab function which deﬁnes the surface z=f(x,y),.The contour function has the following syntax The Scilab function contour plots contours of a function f. This type of graphic is often used in the context of numerical optimization because it draws functions of two variables in a way that shows the location of the optimum. In this section, we present the contour plots of a multivariate function and make use of the contour function. When the number of points to manage is large, using functions directly saves signiﬁcant amount of memory space, since it avoids generating the intermediate vector ydata. Indeed, the second input argument of the plot function can be a function, as in the following session. Notice that we could have produced the same plot without generating the intermediate array ydata. We ﬁnally use the plot function so that the data is displayed as an x-y plot.įigure 21 presents the associated x-y plot. This produces the row vector ydata, which contains 50 entries. We can pass it to the myquadratic function and get the function value at the given points. The xdata variable now contains a row vector with 50 entries, where the ﬁrst value is equal to 1 and the last value is equal to 10. We can use the linspace function in order to produce 50 values in the interval. The myquadratic function squares the input argument x with the ”ˆ”operator. We begin by deﬁning the function which is to be plotted. We emphasize the use of vectorized functions, which produce matrices of data in one function call.

In this section, we present how to produce a simple x-y plot. linspaceĬonﬁgure the title and the legends of the current plotįigure 20: Scilab functions used when creating a plot. The functions presented in ﬁgure 20 will be used in the examples of this section. In order to get an example of a 3D plot, we can simply type the statement surf() in the Scilab console.ĭuring the creation of a plot, we use several functions in order to create the data or to conﬁgure the plot.

The most commonly used plot functions are presented in ﬁgure 19. It can create x-y plots with the plot function, contour plots with the contour function, 3D plots with the surf function, histograms with the histplot function and many other types of plots. Scilab can produce many types of 2D and 3D plots. We ﬁnally export the plots so that we can use it in a report. Then we customize the title and the legend of our graphics. In this section, we present how to create 2D plots and contour plots. Scilab oﬀers many ways to create and customize various types of plots and charts. Producing plots and graphics is a very common task for analysing data and creating reports.

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