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?
Related
Today my problem is this: I have a dataframe of 300 X 41. Its encoded with numbers. I want to append an 'a' to each value in the dataframe so that another down stream program will not fuss about these being 'continuous variables' which they arent, they are factors. Simple right?
Every way I can think to do this though returns a dataframe or object that is not 300x 41...but just one long list of altered values:
Please end this headache for me. How can I do this in a way that returns a 400 X 31 altered output?
> dim(x)
[1] 300 41
>x2 <- sub("^","a",x)
>dim(x2)
[1] 12300 1
I have a question.I have a pandas dataframe that contains 5000 columns and 12 rows. Each row represents the signal received from an electrocardiogram lead. I want to assign 3 labels to this dataset. These 3 tags belong to the entire dataset and are not related to a specific row. How can I do this?
I have attached the picture of my dataframepandas dataframe.
and my labels are: Atrial Fibrillation:0,
right bundle branch block:1,
T Wave Change:2
I tried to assign 3 labels to a large dataset
(Not for a specific row or column)
but I didn't find a solution.
As you see, it has 12 rows and 5000 columns. each row represents 5000 data from one specific lead and overall we have 12 leads which refers to this 12 rows (I, II, III, aVR,.... V6) in my data frame. professional experts are recognised 3 label for this data frame which helps us to train a ML Model to detect different heart disease. I have 10000 data frame just like this and each one has 3 or 4 specific labels. Here is my question: How can I assign these 3 labels to this dataset that I mentioned.as I told before these labels don't refers to specific rows, in fact each data frame has 3 or 4 label for its whole. I mean, How can I assign 3 label to a whole data frame?
I have a dataset with parallel time series. The column 'A' depends on columns 'B' and 'C'. The order (and the number) of dependent columns can change. For example:
A B C
2022-07-23 1 10 100
2022-07-24 2 20 200
2022-07-25 3 30 300
How should I transform this data, or how should I build the model so the order of columns 'B' and 'C' ('A', 'B', 'C' vs 'A', C', 'B'`) doesn't change the result? I know about GCN, but I don't know how to implement it. Maybe there are other ways to achieve it.
UPDATE:
I want to generalize my question and make one more example. Let's say we have a matrix as a singe observation (no time series data):
col1 col2 target
0 1 a 20
1 2 a 30
2 3 b 30
3 4 b 40
I would like to predict one value 'target' per each row/instance. Each instance depends on other instances. The order of rows is irrelevant, and the number of rows in each observation can change.
You are looking for a permutation invariant operation on the columns.
One way of achieving this would be to apply column-wise operation, followed by a global pooling operation.
How that achieves your goal:
column-wise operations are permutation equivariant; that is, applying the operation on the columns and permuting the output, is the same as permuting the columns and then applying the operation.
A global pooling operation (e.g., max-pool, avg-pool) across the columns is permutation invariant: the result of an average pool does not depend on the order of the columns.
Applying a permutation invariant operation on top of a permutation equivariant one results in an overall permutation invariant function.
Additionally, you should look at self-attention layers, which are also permutation equivariant.
What I would try is:
Learn a representation (RNN/Transformer) for a single time series. Apply this representation to A, B and C.
Learn a transformer between the representation of A to those of B and C: that is, use the representation of A as "query" and those of B and C as "keys" and "values".
This will give you a representation of A that is permutation invariant in B and C.
Update (Aug 3rd, 2022):
For the case of "observations" with varying number of rows, and fixed number of columns:
I think you can treat each row as a "token" (with a fixed dimension = number of columns), and apply a Transformer encoder to predict the target for each "token", from the encoded tokens.
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
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