I have a dataset where each case is a student and I have a variable for sex (SEX), as well as one for major (MAJOR). The variable for sex has 2 possible values (male and female), whereas the one for major has dozens (biology, mathematics, etc.).
I would like to use that dataset to create another dataset with one case for each major and 3 variables: MAJOR, MALE and FEMALE. The value of the variable MALE for each major should be the number of men enrolled in that major and the value of the variable FEMALE should be the number of women enrolled in it. The value of MAJOR should just be the label of the value of the variable MAJOR in the original dataset corresponding to that case.
Just so it's clear, when I look at the dataset I would like to create, there should be one line per major, with one column MAJOR that contains the label of each major, one for MALE that contains the number of men enrolled in each major and one column for FEMALE that contains the number of women enrolled in each major.
The dataset I have was created with SPSS and I have never used that program, so I have no idea how to do that, even though it's probably very easy. I would be very grateful for your help!
Best,
Philippe
When your file is open, open a new syntax window, put the following code in it and run it:
dataset name OrigFile.
compute male=(SEX="MALE").
compute female=(SEX="FEMALE").
dataset declare NewFile.
aggregate /outfile='NewFile' /break=major /male female=sum(male female).
after running this you will have two open datasets - you original one and the new one you wanted to create.
Related
I have a dataset in which there are multiple variables for various times.
Here is a sample part of the dataset:
I'm trying to identify the number/percentage of cases that have the same value in any of the multiple variables.
For example, if I have a database of teachers who left a school where they worked and there are variables for why the teacher left each school, how would I find out if a teacher left multiple schools for the same reason. So I have reasonleft1, reasonleft2, reasonleft3, up to 20. Each reasonleft has the same coded response options. For example, 1=better opportunity elsewhere, 2=retired, 3=otherwise left workforce, etc. I'm stumped on how to figure out if any case/teacher left multiple schools for the same reason. Which teachers left multiple schools out of the 20 for 1=better opportunity elsewhere, for example.
Thanks!
This can be done in the following two steps:
You need to restructure the dataset so that each "time" appears in a separate row.
Now you can aggregate to count the number of appearances of each reason per person.
The following syntax will do that:
varstocases
/make facilititype from facilititype1_pre facilititype2_pre facilititype3_pre
/make timeinplace from timeinplace1_pre timeinplace2_pre timeinplace3_pre
/make reasonleft from reasonleft1_pre reasonleft2_pre reasonleft3_pre
/index = timeN(reasonleft).
* you should continue the numbering for as much as needed.
dataset declare MyAgg.
aggregate outfile=MyAgg /break=ID reasonleft/Ntimes=n.
At this point you have a new dataset which has the count of each reason for each ID. If you wish you can go back to wide format, and create a column for each reason (the values in each column are the count of times this reason appeared for the ID).
This way:
dataset activate MyAgg.
casestovars /id=ID /index=reasonleft/separator="_".
I have a bike rental dataset. In this dataset our target variable is Count i.e. total count of bike rental which is the sum of two variables in our dataset i.e casual user count variable and registered user count variable.
So my question is how should i perform modelling on this dataset ?
Please suggest a step as I'm thinking of dropping casual and registered user variable and keeping only count variable as our tagert variable along with other predictor variables
The question is rather vague but I will attempt to answer it.
I am not too sure what it is that you want to predict. Assuming it is the amount of bikes that would be rented out at some future time.
If the distinction between casual and registered is important and has significant meaning to the purpose of your project, then you should probably treat them as separate features and not combine them into one.
On the contrary, if the distinction is not important and you only care for the amount of bikes, then you should be fine combining them and using the total sum.
I think you should try to understand what you are trying to accomplish and what questions you wish to answer with your analysis.
Converted my two target variables into one by summing them up and then created a new model with only one target variable.
What is generally considered the correct approach when you are performing a regression and your training data contains 'incidents' of some sort, but there may be a varying number of these items per training line?
To give you an example - suppose I wanted to predict the likelihood of accidents on a number of different roads. For each road, I may have a history multiple accidents and each accident will have its own different attributes (date (how recent), number of casualties, etc). How does one encapsulate all this information on one line?
You could for example assume a maximum of (say) ten and include the details of each as a separate input (date1, NoC1, date2, NoC2, etc....) but the problem is we want each item to be treated similarly and the model will treat items in column 4 as fundamentally separate from those in column 2 above, which it should not.
Alternatively we could include one row for each incident, but then any other columns in each row which are not related to these 'incidents' (such as age of road, width, etc) will be included multiple times and hence produce bias in the results.
What is the standard method that is use to accomplish this?
Many thanks
I'm looking for a machine learning method to recognize input ranges that result customer dissatisfaction.
For instance, assume that we have a database of customer's age, customer's gender, date and time that customer stops by, person who is in charge of providing service to customer, etc. and finally a number in range of 0 to 10 which stands for customer satisfaction (Extracted from customer's feedback).
Now I'm looking for a method to determine input ranges which results dissatisfaction. For example male customers who are stopping by John, between 10-12pm are mainly dissatisfied.
I believe there already is a kind of clustering or neural network method for this purpose. Could you help me?
This is not a clustering problem. You have training data.
Instead, you may be looking for a decision tree.
There is more than one method to do it (correlation analysis for ex.)
One simple way is to classify your data by the degree of satisfaction (target)
Classes:
0-5 DISSATISFIED
6-10 SATISFIED
Than look for repetition along features in each cluster.
For example:
if you are interested by one feature, ex: the person who stopped clients, than just get the most frequent name within the two classes to get a result like 80% of unsatisfied client was stopped by jhon
if you are interested by more than one feature, ex: the person who stopped the client AND the time of the day, in this case you can consider the couple of features us one and do the same thing as the first case, than you will get something like 30% of unsatisfied client was stopped by jhon between 10 and 11 am
What do you want to know? Which service person to fire, what are the best hours to provide the service, or sth. else? I mean what are your classes?
Provided, you what to evaluate the service person - the classes are the
persons. In SVM (and I think for NN applies the same) I would split all not purely numerical data in boolean attributes.
Age: unchanged, number
Gender: male 1/0, female 1/0
Date: 7 features for days of week, possibly the number of experience days of the service person. for each special date an attribute e.g. national holiday 1/0
Time: split the time-span in reasonable ranges e.g. 15 min. Each range is a feature
Satisfaction: unchanged - number 1-10
With this model you could predict the satisfaction index for each service person for given date, time, gender, age.
I guess, you can try using anomaly detection algorithms. Basically if you consider the satisfaction level as the dependent variable, then you can try to find the samples which are located away from the majority of the samples in the euclidean space. These away samples could signify dissatisfaction.
I am setting some student assignments where most students will be using SPSS. In order to encourage students to do their own work, I want students to have a partially unique dataset. Thus, I'd like to get each to the open the master data file, and then get the student to run a couple of lines of syntax that produces a unique data file. In pseudo code, I'd like to do something like the following where 12345551234 is a student number:
set random number generator = 12345551234
select 90% random subset ofcases and drop the rest.
What is simple SPSS syntax dropping a subset of cases from the data file?
After playing around I came up with this syntax, but perhaps there are simpler or otherwise better suggestions.
* Replace number below with student number or first 10 numbers of student number.
SET SEED=1234567891.
FILTER OFF.
USE ALL.
SAMPLE .90.
EXECUTE.