Below is some data:
Test Day1 Day2 Score
A 1 2 100
B 1 3 62
C 3 4 90
D 2 4 20
E 4 5 80
I am trying to take the values from column 'day' and 'day2' and use them to select the row number for the column score. For example for Test A I would like to find the sum of 100 and 62 because that is the values of the first and second rows of score. Test B I would like to find the sum of 100, 62 and 90.
Is their anyway to do this in the Compute Variable window? Found in the menu Transform-Compute Variable?
I tried the following:
Score(MEAN(VALUE(Day1), VALUE(DAY2)))
This is not the proper way to call the cell location of Score and I received an error.
Can anyone help?
Thank you!
You really have two different datasets here. One is a dataset of scores numbered 1 through 5.
The other is a dataset that includes indexes into the score dataset. So the steps would be something like this.
First take the scores dataset and transpose it so that it has one row and 5 columns (Data>Transpose)
Then match that dataset to each case in the main dataset (Data>Merge Files>Add Variables).
Next you have to resort to using syntax directly.
You would declare a vector for the scores (VECTOR)
Finally, you use COMPUTE to index into the scores.
For your real problem, I suppose that you might have batches of scores and maybe there are some gaps. The Restructure Data Wizard can help you generalize this - convert cases into variables, but let's not go there yet.
HTH,
Jon Peck
Related
I have the following dataset
resulted_by
follow_up_result
follow_up_number
#
%
0
User 1
good
1
30
30
1
User 2
good
2
65
65
2
User 3
bad
3
5
0.05
I want to Pivot:
follow up result and resulted by as indexes
follow up number as a column
# and % as values
pivot = df.head(3).pivot(columns=['follow_up_number'], values=["#", '%'], index=['follow_up_result', 'resulted_by'])
However, I want the follow up number to be above the values, here is how I achieved that:
pivot = df.head(3).pivot(columns=['follow_up_result', 'resulted_by'], values=["#", '%'], index=['follow_up_number'])
pivot = pivot.stack(level=0).T
Notice how I switch columns and indexes.
I want the column names to be at the same level as the values.
Is there a way to do that?
Is there a better way to achieve what I need without switching between columns and indexes?
Code Snippet:
https://onecompiler.com/python/3y5gzm7hu
Lets say i have Dataframe, which has 200 values, prices for products. I want to run some operation on this dataframe, like calculate average price for last 10 prices.
The way i understand it, right now pandas will go through every single row and calculate average for each row. Ie first 9 rows will be Nan, then from 10-200, it would calculate average for each row.
My issue is that i need to do a lot of these calculations and performance is an issue. For that reason, i would want to run the average only on say on last 10 values (dont need more) from all values, while i want to keep those values in the dataframe. Ie i dont want to get rid of those values or create new Dataframe.
I just essentially want to do calculation on less data, so it is faster.
Is something like that possible? Hopefully the question is clear.
Building off Chicodelarose's answer, you can achieve this in a more "pandas-like" syntax.
Defining your df as follows, we get 200 prices up to within [0, 1000).
df = pd.DataFrame((np.random.rand(200) * 1000.).round(decimals=2), columns=["price"])
The bit you're looking for, though, would the following:
def add10(n: float) -> float:
"""An exceptionally simple function to demonstrate you can set
values, too.
"""
return n + 10
df["price"].iloc[-12:] = df["price"].iloc[-12:].apply(add10)
Of course, you can also use these selections to return something else without setting values, too.
>>> df["price"].iloc[-12:].mean().round(decimals=2)
309.63 # this will, of course, be different as we're using random numbers
The primary justification for this approach lies in the use of pandas tooling. Say you want to operate over a subset of your data with multiple columns, you simply need to adjust your .apply(...) to contain an axis parameter, as follows: .apply(fn, axis=1).
This becomes much more readable the longer you spend in pandas. 🙂
Given a dataframe like the following:
Price
0 197.45
1 59.30
2 131.63
3 127.22
4 35.22
.. ...
195 73.05
196 47.73
197 107.58
198 162.31
199 195.02
[200 rows x 1 columns]
Call the following to obtain the mean over the last n rows of the dataframe:
def mean_over_n_last_rows(df, n, colname):
return df.iloc[-n:][colname].mean().round(decimals=2)
print(mean_over_n_last_rows(df, 2, "Price"))
Output:
178.67
I'm trying to group by 2 columns of which the first value has 5 different values and the second 2.
My data looks like this:
and using
df_counted = df_analysis
.groupby(['TYPE', 'RESULT'])
.size()
.sort_values(ascending=False)
.reset_index(name='COUNT')
I was able to transform it into the cases I want:
However I don't want a column for result, just for counts.
It's suppoed to be like
COUNT_TRUE COUNT_FALSE
FORWARD 21 182
BACKWARD 34 170
RIGHT 24 298
LEFT 20 242
NEUTRAL 16 82
The best I could do there was this. How do I get there?
Pandas has a feature of making a pivot table with dataframe. Your task can also be done by making pivot table.
df_counted.pivot_table(index="TYPE", columns="RESULT", values="COUNT")
Result:
Solved it and went a kind of full SQL there. It's not elegant, but it works:
df_counted is the last df from the question with the NaN values.
# drop duplicates for the first counts
df_pos = df_counted.drop_duplicates(subset=['TYPE'], keep='first').drop(columns=['COUNT_POS'])
# drop duplicates for the first counts
df_neg = df_counted.drop_duplicates(subset=['TYPE'], keep='last').drop(columns=['COUNT_NEG'])
# join on TYPE
df = df_pos.set_index('TYPE').join(df_neg.set_index('TYPE'))
If someone has a more elegant way of doing this, I'd be super interested to see it.
I have a dataset that I shaped according to my needs, the dataframe is as follows:
Index A B C D ..... Z
Date/Time 1 0 0 0,35 ... 1
Date/Time 0,75 1 1 1 1
The total number of rows is 8878
What I try to do is create a time-series dendrogram (Example: Whole A column will be compared to whole B column in whole time).
I am expecting an output like this:
(source: rsc.org)
I tried to construct the linkage matrix with Z = hierarchy.linkage(X, 'ward')
However, when I print the dendrogram, it just shows an empty picture.
There is no problem if a compare every time point with each other and plot, but in that way, the dendrogram becomes way too complicated to observe even in truncated form.
Is there a way to handle the data as a whole time series and compare within columns in SciPy?
I have data like this
EmployeeID Value
1 7
2 6
3 5
4 3
I would like to create a DAX calculated column (or do I need a measure?)Â that gives me for each row, Value - AVG() of selected rows.
So if the AVG() of the above 4 rows is 5.25, I would get results like this
EmployeeID Value Diff
1 7 1.75
2 6 0.75
3 5 -0.25
4 3 -1.75
Still learning DAX, I cannot figure out how to implement this?
Thanks
I figured this out with the help of some folks on MSDN forums.
This will only work as a measure because measures are selection aware while calculated columns are not.
The Average stored in a variable is critical. ALLSELECTED() gives you the current selection in a pivot table.
AVERAGEX does the row value - avg of selection.
Diff:=
Var ptAVG = CALCULATE(AVERAGE[Value],ALLSELECTED())
RETURN AVERAGEX(Employee, Value - ptAVG)
You can certainly do this with a calculated column. It's simply
Diff = TableName[Value] - AVERAGE(TableName[Value])
Note that this averages over all employees. If you want to average over only specific groups, then more work needs to be done.