I have a table that has the following data (shortened for this example):
C1 C2 C3
1 0 1 1
2 1 1 0
3 1 0 1
4 1 1 1
5 0 0 1
6 0 0 0
I want to create a create a query that gives me the following result:
C1
C2 sum(C3)
It's similar to a pivot table but it's static.
Could you help me please, I'll be grateful.
Related
I have the following data structure
Y
cum_sum
1
1
1
1
1
1
0
1
0
1
1
1
0
1
1
1
1
1
I would like to have cum_sum change so that it calculates the cumulative sum while Y is unchanged, so that the data is:
Y
cum_sum
1
1
1
2
1
3
0
1
0
2
1
1
0
1
1
1
1
2
Not sure how to do it and I've tried searching but the phrasing I'm using leads me to different questions
* Example generated by -dataex-. For more info, type help dataex
clear
input byte(y cum_sum)
1 1
1 1
1 1
0 1
0 1
1 1
0 1
1 1
1 1
end
replace cum_sum = cum_sum + cum_sum[_n-1] if y == y[_n-1]
I'm looking to create a variable based on this data sample:
Video Subject Pre_post Pre_Post_ID
1 1 0 1
1 2 0 1
1 2 0 1
1 3 0 1
1 3 0 1
2 1 1 1
2 1 1 1
2 2 1 1
2 2 1 1
2 3 1 1
4 1 0 2
4 2 0 2
4 2 0 2
4 3 0 2
4 3 0 2
5 1 1 2
5 1 1 2
5 2 1 2
5 2 1 2
5 3 1 2
The goal of the variable will be to create an ID that links the pre_post variable to the subject on the condition that the pre_post_id is the same:
Video Subject Pre_post Pre_Post_ID Subject_P_P_ID
1 1 0 1 1
1 2 0 1 2
1 2 0 1 2
1 3 0 1 3
1 3 0 1 3
2 1 1 1 1
2 1 1 1 1
2 2 1 1 2
2 2 1 1 2
2 3 1 1 3
4 1 0 2 4
4 2 0 2 5
4 2 0 2 5
4 3 0 2 6
4 3 0 2 6
5 1 1 2 4
5 1 1 2 4
5 2 1 2 5
5 2 1 2 5
5 3 1 2 6
Thank you in advance for the help!
You will want to track the pairs (<pre_post_id>,<subject>) as a composite key and increment the Subject_P_P_ID every time a new pair (or key) is encountered.
To simplify the discussion, call the two items in the pair item1 and item2
Here are two ways:
Sort by item1 item2, step through BY item1 item2 and track pair count using logic based on an automatic first. variable -- pair_id + (first.item2), or
Track pairs as keys of a hash and assign new id as <hash>.num_items + 1 when key lookup fails.
Sort + Data Step + Revert Sort
proc sort data=have out=have_sorted;
by item1 item2;
run;
data have_sequenced;
set have_sorted;
by item1 item2;
item1_item2_pair_id + (first.item2);
run;
proc sort data=have_sequenced out=want;
by video subject pre_post pre_post_id item1_item2_pair_id;
run;
Hash
data want;
set have;
if _n_=1 then do;
declare hash lookup();
lookup.defineKeys('item1', 'item2');
lookup.defineData('item1_item2_pair_id');
lookup.defineDone();
end;
if lookup.find() ne 0 then do;
item1_item2_pair_id = lookup.num_items+1;
lookup.add();
end;
end;
I have a dataframe that looks like:
subgroup value
0 1 0
1 1 1
2 1 1
3 1 0
4 2 0
5 2 0
6 2 0
7 3 0
8 3 1
9 3 0
10 3 0
I need to add a column that add 1 whenever there is at least one value different than 0 in the different subgroups. Please, note that if the value 1 is repeated more than once in the same subgroup, it doesn't affect the count.
The result should be:
subgroup value count
0 1 0 1
1 1 1 1
2 1 1 1
3 1 1 1
4 2 0 1
5 2 0 1
6 2 0 1
7 3 0 2
8 3 1 2
9 3 0 2
10 3 0 2
Thank you in advance for your help!
Using shift with -1 and 1 and cumsum the result
mask=(df.value.ne(df.value.shift()))&(df.value.ne(df.value.shift(-1)))
mask.cumsum()
Out[18]:
0 1
1 1
2 1
3 1
4 1
5 1
6 1
7 1
8 2
9 2
10 2
Name: value, dtype: int32
Using merge and groupby
df.merge(df.groupby('subgroup').value.sum().gt(0).cumsum().reset_index(name='out'))
subgroup value out
0 1 0 1
1 1 1 1
2 1 1 1
3 1 0 1
4 2 0 1
5 2 0 1
6 2 0 1
7 3 0 2
8 3 1 2
9 3 0 2
10 3 0 2
I'm trying to make a shape of random numbers (0 or 1) in this case as I'm trying to create a minesweeper field.
I've tried using the "?" symbol for random to receive it but it normally turns into an unrandom, repeated pattern which for my purposes is unsatisfactory:
5 5 $ ? 0 1
0 1 0 1 0
1 0 1 0 1
0 1 0 1 0
1 0 1 0 1
0 1 0 1 0
Because of this, I tried other ways like pulling numbers from an index (this is called roll). But this returns random decimals. Other small changes to the code also resulted in these random decimals.
I've done this a few times myself. The key thing is when you apply the ?. You get the result that you want if you apply it after the matrix has been created.
We know that ?2 returns a 1 or a 0 value generated randomly.
? 2
0
? 2
1
? 2
0
So if we create a 5X5 matrix of 2's
5 5 $ 2
2 2 2 2 2
2 2 2 2 2
2 2 2 2 2
2 2 2 2 2
2 2 2 2 2
then we apply ? to each 2 in the matrix you get the random 1 or 0 for each position.
? 5 5 $ 2 NB. first 5 X 5 matrix of random 1's and 0's
0 0 0 1 1
1 1 1 0 1
0 0 0 0 1
1 1 1 1 0
1 1 1 0 0
? 5 5 $ 2 NB. different 5 X 5 matrix of random 1's and 0's
0 0 0 1 1
1 0 1 1 0
0 0 0 1 1
1 0 0 1 0
1 1 1 0 0
I'm looking for a J code to do the following.
Suppose I have a list of random integers (sorted),
2 3 4 5 7 21 45 49 61
I want to start with the first element and remove any multiples of the element in the list then move on to the next element cancel out its multiples, so on and so forth.
Thus the output
I'm looking at is 2 3 5 7 61. Basically a Sieve Of Eratosthenes. Would appreciate if someone could explain the code as well, since I'm learning J and find it difficult to get most codes :(
Regards,
babsdoc
It's not exactly what you ask but here is a more idiomatic (and much faster) version of the Sieve.
Basically, what you need is to check which number is a multiple of which. You can get this from the table of modulos: |/~
l =: 2 3 4 5 7 21 45 49 61
|/~ l
0 1 0 1 1 1 1 1 1
2 0 1 2 1 0 0 1 1
2 3 0 1 3 1 1 1 1
2 3 4 0 2 1 0 4 1
2 3 4 5 0 0 3 0 5
2 3 4 5 7 0 3 7 19
2 3 4 5 7 21 0 4 16
2 3 4 5 7 21 45 0 12
2 3 4 5 7 21 45 49 0
Every pair of multiples gives a 0 on the table. Now, we are not interested in the 0s that correspond to self-modulos (2 mod 2, 3 mod 3, etc; the 0s on the diagonal) so we have to remove them. One way to do this is to add 1s on their place, like so:
=/~ l
1 0 0 0 0 0 0 0 0
0 1 0 0 0 0 0 0 0
0 0 1 0 0 0 0 0 0
0 0 0 1 0 0 0 0 0
0 0 0 0 1 0 0 0 0
0 0 0 0 0 1 0 0 0
0 0 0 0 0 0 1 0 0
0 0 0 0 0 0 0 1 0
0 0 0 0 0 0 0 0 1
(=/~l) + (|/~l)
1 1 0 1 1 1 1 1 1
2 1 1 2 1 0 0 1 1
2 3 1 1 3 1 1 1 1
2 3 4 1 2 1 0 4 1
2 3 4 5 1 0 3 0 5
2 3 4 5 7 1 3 7 19
2 3 4 5 7 21 1 4 16
2 3 4 5 7 21 45 1 12
2 3 4 5 7 21 45 49 1
This can be also written as (=/~ + |/~) l.
From this table we get the final list of numbers: every number whose column contains a 0, is excluded.
We build this list of exclusions simply by multiplying by column. If a column contains a 0, its product is 0 otherwise it's a positive number:
*/ (=/~ + |/~) l
256 2187 0 6250 14406 0 0 0 18240
Before doing the last step, we'll have to improve this a little. There is no reason to perform long multiplications since we are only interested in 0s and not-0s. So, when building the table, we'll keep only 0s and 1s by taking the "sign" of each number (this is the signum:*):
* (=/~ + |/~) l
1 1 0 1 1 1 1 1 1
1 1 1 1 1 0 0 1 1
1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 0 1 1
1 1 1 1 1 0 1 0 1
1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1
so,
*/ * (=/~ + |/~) l
1 1 0 1 1 0 0 0 1
From the list of exclusion, you just copy:# the numbers to your final list:
l #~ */ * (=/~ + |/~) l
2 3 5 7 61
or,
(]#~[:*/[:*=/~+|/~) l
2 3 5 7 61
Tacit iteration is usually done with the conjunction Power. When the test for completion needs to be something other than hitting a fixpoint, the Do While construction works well.
In this solution filterMultiplesOfHead is applied repeatedly until there are no more numbers not either applied or filtered. Numbers already applied are accumulated in a partial answer. When the list to be processed is empty the partial answer is the result, after stripping off the boxing used to segregate processed from unprocessed data.
filterMultiplesOfHead=: {. (((~: >.)# %~) # ]) }.
appendHead=: (>#[ , {.#>#])/
pass=: appendHead ; filterMultiplesOfHead#>#{:
prep=: a: , <
unfinished=: [: -. a: -: {:
sieve=: [: ; [: pass^:unfinished^:_ prep
sieve 2 3 4 5 7 21 45 49 61
2 3 5 7 61
prep 2 3 4 7 9 10
┌┬────────────┐
││2 3 4 7 9 10│
└┴────────────┘
appendHead prep 2 3 4 7 9 10
2
filterMultiplesOfHead 2 3 4 7 9 10
3 7 9
pass^:2 prep 2 3 4 7 9 10
┌───┬─┐
│2 3│7│
└───┴─┘
sieve 1-.~/:~~.>:?.$~100
2 3 7 11 29 31 41 53 67 73 83 95 97