Smallmouth bass, walleye, and perch are three common sport fish found in Onondag

Question

Smallmouth bass, walleye, and perch are three common sport fish found in Onondaga Lake. Yellow perch is a plankton-eating fish. Smallmouth bass and walleye are predator fish; they feed on perch. Calculate the average BCF for perch for 1992 and 2008 (data in the spreadsheet from HW 3). Do you observe any change between the two years? Discuss. Calculate the average BAF for smallmouth bass and walleye. Which one has higher BAF? Do you observe any change in BAF between 1992 and 2008? Discuss. Consider an adult and a child who are recreational fishers at Onondaga Lake consuming perch, smallmouth bass, and walleye in 1992 and 2008. (use the data from HW3). Calculate the hazard quotient for non-carcinogenic exposure and determine if their consumption is within the safe levels. Compare the exposure of the recreational fishers with the exposure of the general population who consumes farm fish with methyl mercury concentrations of 0.3 ppm. The RfD for methyl mercury (chronic and subsonic consumption) is 3times10^-4 mg/kg/day. Use the equation provided in Exhibit 8 (Public Health Assessment Guidance Manual, 2005). Consider AF =1 and EF =1.

Explanation / Answer

Ans-

Maxima can use either Gnuplot or Xmaxima as graphics program. Gnuplot is an external program that has to be installed separately, while Xmaxima is distributed with Maxima. There are various different formats for those programs, which can be selected with the option plot_format (see also thePlotting Options section).

The plotting formats are the following:

Used to launch the external program gnuplot, which must be installed in your system. All plotting commands and data are saved into the filemaxout_xxx.gnuplot.

This format is not available in Windows platforms. It is similar to the gnuplot format except that the commands are sent to gnuplot through a pipe, while the data are saved into the file maxout_xxx.gnuplot_pipes. A single gnuplot process is kept open and subsequent plot commands will be sent to the same process, replacing previous plots, unless the gnuplot pipe is closed with the function gnuplot_close. When this format is used, the function gnuplot_replot can be used to modify a plot that has already displayed on the screen.

This format is only used to plot to the screen; whenever graphic files are created, the format is silently switched to gnuplot and the commands needed to create the graphic file are saved with the data in file maxout_xxx.gnuplot.

Mgnuplot is a Tk-based wrapper around gnuplot. It is included in the Maxima distribution. Mgnuplot offers a rudimentary GUI for gnuplot, but has fewer overall features than the plain gnuplot interface. Mgnuplot requires an external gnuplot installation and, in Unix systems, the Tcl/Tk system.

Xmaxima is a Tcl/Tk graphical interface for Maxima that can also be used to display plots created when Maxima is run from the console or from other graphical interfaces. To use this format, the xmaxima program, which is distributed together with Maxima, should be installed. If Maxima is being run from the Xmaxima console, the data and commands are passed to xmaxima through the same socket used for the communication between Maxima and the Xmaxima console. When used from a terminal or from graphical interfaces different from Xmaxima, the commands and data are saved in the file maxout_xxx.xmaxima and xmaxima is run with the name of that file as argument.

In previous versions this format used to be called openmath; that old name still works as a synonym for xmaxima.

Categories:  Plotting

12.3 Functions and Variables for Plotting

Function: contour_plot (expr, x_range, y_range, options, …)

It plots the contours (curves of equal value) of expr over the region x_range by y_range. Any additional arguments are treated the same as inplot3d.

This function only works when the plot format is either gnuplot or gnuplot_pipes. The additional package implicit_plot, which works in any graphic format, can also be used to plot contours but a separate expression must be given for each contour.

Examples:

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