From: Benjamin R. <ben...@ou...> - 2010-06-08 19:36:05
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Waléria, I repeat, you need to add parentheses for the denominator of that quantity in order to match what you wrote out on paper. You are missing a set of parentheses that is causing (3e14**2) to be *multiplied* rather than divided. This explains the huge values you are getting. Ben Root On Tue, Jun 8, 2010 at 2:05 PM, Waléria Antunes David < wal...@gm...> wrote: > no, I think, did not understand my functions.....see....i made a change my > second function in the attached. > > > On Tue, Jun 8, 2010 at 3:48 PM, Benjamin Root <ben...@ou...> wrote: > >> I think I found your errors. >> >> First, you are correct, the scientific notation in python is as you >> understand, there is nothing wrong with that. >> >> Instead, you have a problem with order of operations. In the last >> quantity, you have "((x**2)/4*(1e4**2)*(3e14**2))" >> According to the equation that you wrote out in the attached image, you >> need: "((x**2)/*(*4*(*2*e4**2)*(3e14**2))*)*" >> Note that you needed parentheses for the entire denominator. Also, the >> 1e4**2 should have been 2e4**2. >> >> This gives me values between 4.3125e-48 and 5.5359e-48. >> >> Ben Root >> >> On Tue, Jun 8, 2010 at 12:47 PM, Waléria Antunes David < >> wal...@gm...> wrote: >> >>> I understand what you are saying, but my functions are these, attached. >>> >>> >>> >>> >>> >>> >>> Scientific notation in Python is not so? >>> >>> *Math * *Python* >>> >>> >>> >>> >>> >>> >>> Pinc = 10-6 Pinc = 1e-6 >>> >>> 3,0x1014 3e14 >>> >>> >>> >>> >>> >>> ? >>> >>> >>> Then, changing my functions of the images attached for python is as bellow: >>> >>> >>> >>> >>> >>> >>> y1 = -108*(x**2)/(3e14**2) >>> >>> y2 = 1*((1.38e-23*(1e0+4)/1e-6)*((x**2)/4*(1e4**2)*(3e14**2)))) >>> >>> Is not it? >>> >>> >>> >>> >>> >>> >>> On Tue, Jun 8, 2010 at 1:34 PM, Gökhan Sever <gok...@gm...>wrote: >>> >>>> >>>> >>>> On Tue, Jun 8, 2010 at 10:19 AM, Waléria Antunes David < >>>> wal...@gm...> wrote: >>>> >>>>> Hello!!! >>>>> >>>>> My name is Waleria. I work at INPE in Sao Jose dos Campos, Brazil. And >>>>> I'd like to make a question. I'm in trouble to generate a two functions >>>>> graph. >>>>> >>>>> I have a problem to generate a graph of the two functions. I have this >>>>> functions, is bellow: >>>>> >>>>> *y1 = -108*(x**2)/(3e14**2)* >>>>> >>>>> *y2 = 1*((1.38e-23*(1e0+4)/1e-6)*((x**2)/4*(1e4**2)*(3e14**2))))* >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> You might need to check your y2. You are mixing integers and floats >>>> which possible have resulted with some rounding errors. I get e+30 when I >>>> assert the terms as floats in y2. >>>> >>>> For the plotting: y1 is around -e-20 whereas y2 goes up to e+30. You >>>> can't see the trend easily on one axes even if you could scale >>>> them logarithmically (hint logarithm is only defined for positive numbers). >>>> You can make a positive assumption for the y1 and plot them on one y-axes >>>> >>>> yscale('log') >>>> axis(ymin=1e+20, ymax=1e+30) >>>> >>>> Still this won't let you see the functions trends that you are looking >>>> to see. I would suggest you to use multipe figures or investing a bit more >>>> time to use parasite axes example of JJ. >>>> >>>> >>>> >>>> >>>> -- >>>> Gökhan >>>> >>> >>> >>> >>> ------------------------------------------------------------------------------ >>> ThinkGeek and WIRED's GeekDad team up for the Ultimate >>> GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the >>> lucky parental unit. See the prize list and enter to win: >>> http://p.sf.net/sfu/thinkgeek-promo >>> _______________________________________________ >>> Matplotlib-users mailing list >>> Mat...@li... >>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users >>> >>> >> > |