Re: Designing a Flexible Mathematica Program for Data Analysis

*To*: mathgroup at smc.vnet.net*Subject*: [mg74697] Re: Designing a Flexible Mathematica Program for Data Analysis*From*: Peter Pein <petsie at dordos.net>*Date*: Sun, 1 Apr 2007 04:13:36 -0400 (EDT)*References*: <eul01m$87b$1@smc.vnet.net>

5000brians schrieb: > I'm using Mathematica to perform data analysis for a project I've been > working on for a few years. I have written quite a bit of Mathematica > code for automating the task of analyzing the data. > > As time goes by, the type of data I collect changes slightly. I'm > looking for a way for the various data set types I have to happily > coexist within a single Mathematica session so I can compare and > contrast all the data with a minimum of fuss. > > Let's say I want to create a plot of dataset 1 and dataset 2. In both > cases, I want the same thing, a plot of parameter a versus parameter > b. And let's say I have a bunch of code already written and it works > just fine for dataset 1. But, dataset 2 is newer, and the data format > is slightly different. The parameters a and b mean the same thing in > both cases, it's just that they are represented differently in dataset > 2 than in dataset 1. > > And let's say I have the following functions: > readDataset: opens the text file and puts dataset into memory > generateAandB: based on the data in the dataset, creates a list of > parameters a and b for a dataset > plotAandB: creates a plot of a vs b. > > In this case, I probably need two versions of readDataset and > generateAandB, one for each of my dataset types. If I am using a > List[], I am probably ok with one plotAandB function. > > But how can I automate this solution? What if I want to read in 30 > datasets with 10 different dataset types? > > I can't do plotAandB[generateAandB[readDataset[#]]]& /@ > listOfDatasets, because I need 10 different generateAandBs and 10 > different readDatasets. > > How can I make my code "datatype aware"? > > I know this is a bit long winded - sorry about that. > > Thanks for any help, > Brian > > Hi Brian, I would prepend the data in the files with the names of the functions to use (which should be defined in the notebook). A simple example with only one (undefined) function for each dataset. In[1]:=SetDirectory[StringJoin[$HomeDirectory, "\\Desktop"]]; In[2]:= tb = Import["data1.txt", "Table"] Apply[ToExpression[tb[[1,1]]], Rest[tb], {1}] Out[2]={{"ReadFunction1"}, {1, 1},{2, 4}, {3, 9}, {4, 16}} Out[3]= {ReadFunction1[1, 1], ReadFunction1[2, 4], ReadFunction1[3, 9], ReadFunction1[4, 16]} In[4]:= tb = Import["data2.txt", "Table"] Apply[ToExpression[tb[[1,1]]], Rest[tb], {1}] Out[4]= {{"ReadFunction2"}, {1, 1}, {4, 2}, {9, 3}, {16, 4}} Out[5]= {ReadFunction2[1, 1], ReadFunction2[4, 2], ReadFunction2[9, 3], ReadFunction2[16, 4]} Peter