Using polychoric command - database

I need some help with Stata. I'm using the polychoricpca command in stata because my variables are categorical. I write the following command in stata: polychoricpca var1 var2 ... , score(index) nscore(n)
However, the results appear incomplete: the eigenvectors don't appear and besides, I can't do the rotation. Can anyone familiar with this command help me do this analysis?

Related

Looping through a set of variables for R package analysis

Here's a novice question..being new to R this has got to be.
I am trying to run an R package that analyzes "csv" data using the following R scripts:
library(agricolae)
LXTOUTPUT2<-with(RLINXTES2, lineXtester(Replication, Lines, Tester, Y))
All elements analyzed by the function "lineXtester" are numerics.
Analyzing 1 variable is fine. However, I have several variables to supply as "Y" and would like to run this through as one chunk.
I tried the "for loop" but couldn't find the right script that would cycle thru all variables.
Instead of "for loop" is there a better, faster option? I read about "vectorizing" but R is still a strange stuff for me.
Would greatly appreciate your help.
Thank you.
My sincere apology. I was finally able to figure out my problem by reading and learning more about "vectorization" and applying it to my dataframe and accessing the elements using the [[]] indexing.
Indeed, it is much simpler and faster than using the "for loop".
Please disregard my request for help.
Thank you just the same.

SPSS loop ROC analysis for lots of variables

In SPSS, I would like to perform ROC analysis for lots of variables (989). The problem, when selecting all variables, it gives me the AUC values and the curves, but a case is immediately excluded if it has one missing value within any of the 989 variables. So, I was thinking of having a single-variable ROC analysis put into loop. But I don't have any idea how to do so. I already named all the variables var1, var2, var3, ..., var988, var989.
So, how could I loop a ROC analysis? (Checking "Treat user-missing values as valid" doesn't do the trick)
Thanks!
this sounds like a job for python. Its usually the best solution for this sort of job in SPSS.
So heres a framwork that might help you. I am woefully unfamiliar with ROC-Analysis, but this general pattern is applicable to all kinds of looping scenarios:
begin program.
import spss
for i in range(spss.GetVariableCount()):
var = spss.GetVariableName(i)
cmd = r'''
* your variable-wise analysis goes here --> use spss syntax, beetween the three ' no
* indentation is needed. since I dont know what your syntax looks like, we'll just
* run descriptives and frequencies for all your variables as an example
descriptives %(var)s
/sta mean stddev min max.
fre %(var)s.
'''%locals()
spss.Submit(cmd)
end program.
Just to quickly go over what this does: In line 4 we tell spss to do the following as many times as theres variables in the active dataset, 989 in your case. In line 5 we define a (python) variable named var which contains the variable name of the variable at index i (0 to 988 - the first variable in the dataset having index 0). Then we define a command for spss to execute. I like to put it in raw strings because that simplifies things like giving directories. A raw string is defined by the r''' and ends at the '''. in line 12. "spss.Submit(cmd)" gives the command defined after "cmd = " to spss for execution. Most importantly though, whenever the name of the variable would appear in your syntax, substitute it with "%(var)s"
If you put "set mprint on." a line above the "begin program." youll see exactly what it does in the viewer.

SPSS: Use index variable inside quotation marks

I have several datasets over which i want to run identical commands.
My basic idea is to create a vector with the names of the datasets and loop over it, using the specified name in my GET command:
VECTOR=(9) D = Name1 to Name9.
LOOP #i = 1 to 9.
GET
FILE = Directory\D(#i).sav
VALUE LABELS V1 to V8 'some text D(#i)'
LOOP END.
Now SPSS doesn't recognize that i want it to use the specific value of the vector D.
In Stata i'd use
local D(V1 to V8)
foreach D{
....`D' .....
}
You can't use VECTOR in this way i.e. using GET command within a VECTOR/LOOP loop.
However you can use DEFINE/!ENDDEFINE. This is SPSS's native macro facility language, if you are not aware of this, you'll most likely need to do a lot of reading on it and understand it's syntax usage.
Here's an example:
DEFINE !RunJob ()
!DO !i !IN 1 !TO 9
GET FILE = !CONCAT("Directory\D(",#i,").sav").
VALUE LABELS V1 to V8 !QUOTE(!ONCAT("some text D(",#i,")",
!DOEND
!ENDDEFINE.
SET MPRINT ON.
!RunJob.
SET MPRINT OFF.
All the code between DEFINE and !ENDDEFINE is the body of the macro and the syntax near to the end !RunJob. then runs and executes those procedures defined in the macro.
This a very simply use of a macro with no parameters/arguments assigned but there is scope for much more complexity.
If you are new to DEFINE/!ENDEFINE I would actually suggest you NOT invest time in learning this but instead learn Python Program ability which can be used to achieve the same (and much more) with relative ease compared to DEFINE/!ENDDEFINE.
A python solution to your example would look like this (you will need Python Programmability integration with your SPSS):
BEGIN PROGRAM.
for i in xrange(1,9+1):
spss.Submit("""
GET FILE = Directory\D(%(i)s).sav
VALUE LABELS V1 to V8 'some text D(%(i)s)'.""" % locals())
END PROGRAM.
As you will notice there is much more simplicity to the python solution.
#Caspar: use Python for SPSS for such jobs. SPSS macros have been long deprecated and had better be avoided.
If you use Python for this, you don't even have to type in the file names: you can simply look up all file names in some folder that end with ".sav" as shown in this example.
HTH!
The Python approach is as Ruben says much superior to the old macro facility, but you can use the SPSSINC PROCESS FILES extension command to do tasks like this without any need to know Python. PROCESS FILES is included in the Python Essentials in recent versions of Statistics but can be downloaded from the SPSS Community website (www.ibm.com/developerworks/spssdevcentral) in older versions.
The idea is that you create a syntax file that works on one data file, and PROCESS FILES iterates that over a list of input files or a wildcard specification. For each file, it defines file handles and macros that you can use in the syntax file to open and process the data.

How do I run a C program several times and record the outputs?

so basically I have a C program which does a lot of computation based on an input .txt file and outputs a value. I want to run it 100 times and then work out the average, obviously this would be tedious to do individually.
So I've tried to research a bit about scripting etc and I've found things like this:
https://answers.yahoo.com/question/?qid=20091206100348AAaJPP8
Am I supposed to just do this in my command prompt? (I'm on Windows btw)
Thanks for any help :)
You're on Windows, so you can use a DOS batch script (.bat) to run your program N times using a loop (or N separate commands if that's easier for you). Use the >> symbol at the end of the command to append the output to a file. See http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/redirection.mspx?mfr=true for more info on this, and search google for dos bat file for help on getting started with writing batch scripts.
Try this:
Have the program append the data into the text or csv file concerned and then write another program where you can run the program for a defined number of times. Use the function system(). It accepts a string as argument and executes it in the CUI.
Hope that helps.

Trace and log values of a variable with GDB

I am not an experienced programmer but I recently have to check C code translated from Matlab, in order to ensure that with the same data set, C and Matlab are giving the identical results.
Watches are what I am able to use until now but that requires me to sit in front of the screen and watch the values of a variable change at each loop. Is there a way to trace and log the values of a variable into a .txt file so that I can plot it later to compare with the results from Matlab?
I have already tried to write the values into some .txt file with 'fwrite' but there is not the ideal solution as I have to do that in the C code that I want to check. Embarrassed I am currently reading about tracepoint of gdb and will try to use that but I am still unsure if that is what I need. If you have some tips about what else I try.
I´m using Windows 7 and work with CodeBlocks.
Thanks!
Christina
You can set a breakpoint command to run when your watchpoint hits; have it log and execute a continue command to let the program keep running.

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