Excel 365 allows to multiply ranges to get an array as a result.
Example:
#
A
B
C
1
1
0
1
2
0
1
1
Entering in A3
= A1:C1 * A2:C2
will evaluate to {1,0,1} * {0,1,1}
and return an array {0,0,1} spilling in A3:C3
#
A
B
C
3
0
0
1
This operation can also be used in formulas, especially useful in FILTER(), SUMPRODUCT() etc.
Is there a formula in Excel 365 that can take as arguments an arbitrary number of 1-D ranges, multiply them, and return a 1-D array in the same way as above?
For what I found out so far, SUMPRODUCT() and MMULT() can return only a single value, not a 1-D array.
Alternatively, I can write a LAMBDA, but would like to avoid it, if there is a ready-made formula for it.
I am not 100% what do you mean, I would assume you want to multiply all rows of the same column and return a row array with the result per column. You can achieve it in cell E1 using the following formula:
=BYCOL(A1:C3, LAMBDA(col, PRODUCT(col)))
and here is the output:
If you have only positives numbers, then you can use MMULT, based on the following mathematical properties:
Putting in excel terms using EXP/LN functions in our case it would be:
=EXP(MMULT(TOROW(ROW(A1:C3)/ROW(A1:C3)), LN(A1:C3)))
or using LET to avoid repetitions:
=LET(rng, A1:C3, rows, ROW(rng), u, TOROW(rows/rows), EXP(MMULT(u, LN(rng))))
You get the same result.
Note: rows/rows just returns the unit vector with the same number of rows as A1:C3.
Related
I have array A (44x1) and B (41x1), and I want to count for both arrays how many times the elements are repeated. And if the repeated values are present in both arrays, I want their counting to be divided (for instance: value 0.5 appears 500 times in A and 350 times in B, so now divide 500 by 350).
I have to do this for bigger arrays as well, so I was thinking about using a looping (but no idea how to do it on MATLAB).
I got what I want on python:
import pandas as pd
data1 = pd.read_excel('C:/Users/Desktop/Python/data1.xlsx')
data2 = pd.read_excel('C:/Users/Desktop/Python/data2.xlsx')
for i in data1['Mag'].value_counts() & data2['Mag'].value_counts():
a = data1['Mag'].value_counts()/data2['Mag'].value_counts()
print(a)
break
Any idea of how to do the same on MATLAB? Thanks!
Since you can enumerate all valid earthquake magnitude values, you could use:
% Make up some data
A=randi([2 58],[100 1])/10;
B=randi([2 58],[20 1])/10;
% Round data to nearest tenth
%A=round(A,1); %uncomment if necessary
%B=round(B,1); %same
% Divide frequencies
validmags=0.2:0.1:5.8;
Afreqs=sum(double( abs(A-validmags)<1e-6 ),1); %relies on implicit expansion; A must be a column vector and validmags must be a row vector; dimension argument to sum() only to remind user; double() not really needed
Bfreqs=sum(double( abs(B-validmags)<1e-6 ),1); %same
Bfreqs./Afreqs, %for a fancier version: [{'Magnitude'} num2cell(validmags) ; {'Freq(B)/Freq(A)'} num2cell(Bfreqs./Afreqs)].'
The last line will produce NaN for 0/0, +Inf for nn/0, and 0 for 0/nn.
You could also use uniquetol, align the unique values of each vector, and divide the respective absolute frequencies. But I think the above approach is cleaner and easier to understand.
So I m trying to find some alternative to sumifs in excel where each condition needs to be checked in a 2D range instead of a 1D range.
For example, in the below table I want the sum of values in column V for rows where A12 ("IJ") is present in range A2:C8 (P), B12 ("NM") is present in the range D2:F8 (S) and C12 ("XX") is present in range G2:I8 (A)
I am trying to find a solution involving an array-based formula (without VBA).
Like for example in the below-given formulas,
SUMPRODUCT((B2:B8'=A12)*J2:J8) will give an array-based calculation as follows
SUMPRODUCT({TRUE;FALSE;TRUE;FALSE;FALSE;TRUE;FALSE}*{22;79;45;67;43;72;52})
= SUMPRODUCT({22;0;45;0;0;72;0})
=139
It is easy when there is only one condition needs to be checked but like sumifs, I intend to check multiple conditions, but as soon as I add other conditions, the array becomes multidimensional and gives the wrong answer.
Example:
SUMPRODUCT((A2:C8=A12)*(D2:F8=B12)*J2:J8) breaks down to
=SUMPRODUCT(
{FALSE,TRUE,FALSE;FALSE,FALSE,FALSE;FALSE,TRUE,FALSE;FALSE,FALSE,FALSE;FALSE,FALSE,FALSE;FALSE,TRUE,FALSE;FALSE,FALSE,FALSE}*
{TRUE,FALSE,FALSE;FALSE,FALSE,FALSE;TRUE,FALSE,FALSE;FALSE,FALSE,FALSE;FALSE,FALSE,FALSE;TRUE,FALSE,FALSE;FALSE,FALSE,FALSE}
*J2:J8)
in the background what is happening is (example for 3rd row)
SUMPRODUCT( ({FALSE, TRUE ,FALSE} * {TRUE,FALSE,FALSE}) * 45 )
= SUMPRODUCT({FALSE,FALSE,FALSE} *45 )
=0
SUMPRODUCT(({FALSE,TRUE ,FALSE} + {TRUE,FALSE,FALSE}) * 45 )
= SUMPRODUCT({TRUE,TRUE,FALSE} *45 )
= 90
#expected answer =45
Can someone help me understand where I am going wrong or what I am missing?
If there is any other way then suggestions are always welcome.
Please note this is a dummy data actual data is very big for each header (P,S,A) there are values in 10 columns respectively and the number of rows is also very large.
Try this...
=SUMPRODUCT( ((A2:A8=A12)+(B2:B8=A12)+(C2:C8=A12)) * ((D2:D8=B12)+(E2:E8=B12)+(F2:F8=B12)) * ((G2:G8=C12)+(H2:H8=C12)+(I2:I8=C12)) * J2:J8 )
For SUMPRODUCT to work, the shape of the Boolean array needs to match the shape of the array you wish to conditionally sum.
J2:J8 is seven rows tall by one column wide.
The above formula creates an array of 1s and 0s from your three criteria ranges and shapes it into seven rows tall by one column wide.
At that point, SUMPRODUCT can do it's normal thing because the criteria array matches the dimension of the sum array J2:J8.
I'm trying to create a list of 50 random numbers let's say between 100 and 500 with one formula in Gsheets. Is there any formula like 'apply this to x cells'?
What I tried so far is (and doesn't work). I hoped randarray function will 'force' randbetween function to create 2D array (randarray creates a list of numbers between 0 and 1).
={
RANDARRAY(50,1), ARRAY_CONSTRAIN(RANDBETWEEN(100,500),50,1)
}
Error
Function ARRAY_ROW parameter 2 has mismatched row size. Expected: 50. Actual: 1.
So this error indicates that array_constrain didn't help either.
try like this:
=ARRAYFORMULA(RANDBETWEEN(ROW(A100:A149), 500))
In generic terms, if you need N random numbers, between X and Y, you would combine the following formulas:
RandBetween(X, Y)
Row(cell_ref)
Indirect(string_cell_ref)
ArrayFormula(array_formula)
Details
When combining a Row(cell_ref) with an ArrayFormula, you can specify a cell range or simply a number range:
ArrayFormula(Row(1:50))
The above example generates a one dimensional array (column) with the numbers 1 through 50. In order to programmatically change the number, we use the Indirect function to specify the upper bound of the range, N:
ArrayFormula(Row(Indirect("1:"&N)))
N can be a named range, hard coded, or a cell reference containing a number greater than 0. Because you want each row to contain a random number between X and Y, you need to eliminate the sequential number in each array position by multiplying the number generated by the above formula by zero:
ArrayFormula(Row(Indirect("1:"&N))*0)
which generates a on dimensional array (column) of N zeros. Now you can combine this as follows to generate a one dimensional array (column) of N random numbers between X and Y:
Solution
ArrayFormula(RandBetween(Row(Indirect("1:"&N))*0+X, Y))
You could use named ranges for N, X, and Y; hard code them eg. 50, 100, 500; or use simple cell references as in the example below:
ArrayFormula(RandBetween(row(indirect("1:"&B1))*0+B2, B3))
GSheet Example
I have an Excel spreadsheet, contain all possible combinations between certain products, e.g. a-a, a-b, a-c, b-a, b-b, b-c, c-a, c-b and c-c. Based on those combinations, a value is calculated and compared with a historical value. The two values are subtracted, resulting in -1, 0 or 1.
Now, in another spreadsheet, I have all the products listed (so that would be a, b and c here) and for each product, I would like to know how many -1's, 0's and 1's the product had as a result when it was the second product in the combination, e.g. I want to know how many ...-b's resulted in 0.
My first thought was to use a simple COUNTIF, going over the range with the subtraction: COUNTIF(RANGE:0). Of course, this gives all the 0's in the range, without taking into account the product. Then, I tried SUM(IF(AND("range of the second product"="b";"range of the subtraction result"=0);1)), but this produces #N/A. I am unsure what to try out next.
In some other related topics, the suggestion was made to make use of arrays, based on http://www.cpearson.com/excel/ArrayFormulas.aspx
Consequently, I tried the formula {=COUNT(("2ndproductrange"="b") * ("resultrange"<0))}, but this returned the total number of rows. A variant with {=COUNTIF(("2ndproductrange"="b")*("resultrange");<0)} isn't a valid formula.
It sounds like to me that you are trying to perform a COUNT operation that matches 2 distinct criteria. As you noted the COUNTIF formula takes in a single criteria, well there is a COUNTIFS formula that takes in multiple. Here is what I "think" it would look like with your example ranges:
=COUNTIFS(2ndproductrange;"b";resultrange;"<0")
A concrete example would be as follows:
A B C D E F G
---------------------------------------------------------
Historical Value Product Countifs a b c
1 c <0 1 2 0
-1 a 0 0 1 1
-1 b >0 1 2 1
1 b
1 b
0 c
-1 b
0 b
1 a
In the above example the formulas would be:
=COUNTIFS($B:$B;"a";$A:$A;"<0") =COUNTIFS($B:$B;"b";$A:$A;"<0") =COUNTIFS($B:$B;"c";$A:$A;"<0")
=COUNTIFS($B:$B;"a";$A:$A;"0") =COUNTIFS($B:$B;"b";$A:$A;"0") =COUNTIFS($B:$B;"c";$A:$A;"0")
=COUNTIFS($B:$B;"a";$A:$A;">0") =COUNTIFS($B:$B;"b";$A:$A;">0") =COUNTIFS($B:$B;"c";$A:$A;">0")
For those that are using a comma , as their list separator locale the same formulas would be:
=COUNTIFS($B:$B,"a",$A:$A,"<0") =COUNTIFS($B:$B,"b",$A:$A,"<0") =COUNTIFS($B:$B,"c",$A:$A,"<0")
=COUNTIFS($B:$B,"a",$A:$A,"0") =COUNTIFS($B:$B,"b",$A:$A,"0") =COUNTIFS($B:$B,"c",$A:$A,"0")
=COUNTIFS($B:$B,"a",$A:$A,">0") =COUNTIFS($B:$B,"b",$A:$A,">0") =COUNTIFS($B:$B,"c",$A:$A,">0")
We have a project on a certain math subject and I am done with the computations and it works just fine. So the task is, let's say you have a system of linear equations of certain number of unknowns, you input the number of unknowns, and fill in the values, and using matrix computations, find all the value of unknowns.
To make this short, I already finished the "find the value of unknowns" along with the computation, I checked it, and it seems fine. I can put 6 as the number of unknowns and it automatically computes the inverse of a 6x6 matrix and it will return the 6 unknown values using Index INDIVIDUALLY.
(Note: We aren't allowed to use VBA or Macros since we haven't discussed that yet.
The problem is, I don't know how to automatically fill a RANGE of cells with a VALUE or A FORMULA based on a SINGLE cell value.
For example, In cell A1, I will input 5 (which indicates the number of unknowns), then upon inputting this and hitting enter, let's say a range of cells A2 to A6 (which is 5 cells) will be automatically filled with incremented letters, like for A2 -> A ; A3 -> B ; ... A6 -> E, of which these letters indicate the 5 unknowns.
PROBLEM 2.
Another follow up question, let's say I input again 5, which again stands for the number of missing values/unknowns, in A1, besides the column of the variables A,B,C,D,E (5 unknowns), I want to automatically fill column B respectively with values from an array.
This is just the same with my first problem but this time, instead of incremented letters, it would be Incremented Index function.
For example: I input 5
*Column A will automatically be filled with the variables/letters
*Column B will automatically be filled with the values from an array that's computed using a formula but is not shown independently on cells.
I already have the formula
INDEX(Formula I created, Row number of the answer from the Formula I created , Column number of the answer from the formula I created)
The answers from the formula I made myself is also an array, an "n" rows and 1 column array. If I put the Index formula on a SINGLE cell, it returns specified row number value from the array that resulted in the computation from my formula
What I want is for example, for 5 unknowns
**A | B**
1|.......5..........................
2|.......A..............Some Value 1
3|.......B..............Some Value 2
4|.......C..............Some Value 3
5|.......D..............Some Value 4
6|.......E..............Some Value 5
Wherein the "Some Value" is the Arrayed Answer from my formula and the "1,2,3,4,5" specifies the row number from that arrayed answer.
This is upon inputting the matrix values, inputting the number of unknowns "n" in A1, and automatically filling a range of cells A2 to A"n" with letters A up to what letter "n" corresponds, and automatically filling a range of Cells B2 to B"n" with my formula but with incremented row number for every row in the Index(Formula, Row number , Column number) function.
Note: I hope there's a way to do this using excel functions only since we haven't discussed VBA or Macros yet so we can't use those, and even If we can, I have no knowledge for that. haha. :D
THANK YOU THANK YOU THANK YOU SO MUCH IN ADVANCED! Cheers. :D
Here's a formula for column A:A (write this in cell A2) and drag down:
=IF(ROW()-1<=$A$1,CHAR(ROW()+63),"")