/** * Evaluate a function at a specific point in x * * @param vars Values for evaluation separated by commas, x=1,y=2,z=3 * @return function value at x */ public double eval(String vars) { // get all variables String[] tmp = vars.split(","); // double[] vd = new double[tmp.length]; for (int i = 0; i < tmp.length; i++) { String[] vv = tmp[i].split("="); if (vv.length != 2) { ErrorMessage("Error in parsing list of input variablse. Did you use val=number? "); } try { double d = Double.valueOf(vv[1].trim()).doubleValue(); jep.addVariable(vv[0].trim(), d); } catch (NumberFormatException nfe) { System.out.println("NumberFormatException: " + nfe.getMessage()); } } try { Object result = jep.evaluate(node); if (result instanceof Double) { return ((Double) jep.evaluate(node)).doubleValue(); } } catch (ParseException e) { return 0; } return 0; }
/** * Evaluate a function at a specific point for one single variable. Evaluation is done between * xmin and xmax * * @param indvars Define independent variable, like 'x' Only one variable is allowed * @param xmin xmin value for independent varible * @param xmax xmax value for independent varible * @param vars define values for other variables, like 'y=1,z=3' * @return true if no errors */ public boolean eval(String indvars, double xmin, double xmax, String vars) { String name = proxy.getName(); int points = proxy.getPoints(); boolean suc = true; String[] tmp = vars.split(","); // double[] vd = new double[tmp.length]; fixedVars = vars; for (int i = 0; i < tmp.length; i++) { String[] vv = tmp[i].split("="); if (vv.length != 2) { ErrorMessage("Error in parsing list of input variablse. Did you use val=number? "); } try { double d = Double.valueOf(vv[1].trim()).doubleValue(); jep.addVariable(vv[0].trim(), d); } catch (NumberFormatException nfe) { System.out.println("NumberFormatException: " + nfe.getMessage()); suc = false; } } double min = xmin; double max = xmax; x = new double[points]; y = new double[points]; for (int i = 0; i < points; i++) { x[i] = min + i * (max - min) / (points - 1); jep.addVariable(indvars.trim(), x[i]); try { Object result = jep.evaluate(node); if (result instanceof Double) { y[i] = ((Double) jep.evaluate(node)).doubleValue(); } } catch (ParseException e) { jhplot.utils.Util.ErrorMessage( "Failed to parse function " + name + " Error:" + e.toString()); suc = false; } } if (suc) isEvaluated = true; return suc; } // end 1-D evaluation