 ## Category: R multiply multiple columns by constant

In Excel, most of us may suffer to multiply two columns and then add them up, of course, we can multiply each items and then sum them, but this will be troublesome if there are hundreds or thousands rows need to calculate. This article, I will talk about how to apply this function. Multiply two columns and then sum without criteria. Multiply two columns and then sum based on criteria. Kutools for Excel : with more than handy Excel add-ins, free to try with no limitation in 60 days. Download and free trial Now!

Supposing you have the following data range which you need to multiply the quantity column and unit price and then add up all the multiply results together to get the total price:.

### Vector Arithmetics

Multiply two columns and then sum with one criterion. Multiply two columns and then sum with more criteria.

Multiply two columns and then sum based on multiple criteria in multiple columns. Multiply two columns and then sum based on multiple criteria in the same column. Note : The above examples are some basic formulas, you can add more criteria as you need within the basic formula. Log in. Remember Me Forgot your password? Forgot your username? Password Reset. Please enter the email address for your account. A verification code will be sent to you. Once you have received the verification code, you will be able to choose a new password for your account.

This is where the elements in the same row are multiplied by one another. It will have the same number of rows as the first matrix x has 1 row and the same number of columns as the second matrix c has 2 columns. The previous operations were done using the default R arrays, which are matrices.

We can confirm this using the command class and typeof below:. Remember data frames in R can hold different types of data numbers, letters, etc.

Note that there is an extra column of numbers from 1 to 3 for both c1 and x1. This is just a feature of the data frame output in R, where it is counting the rows 1 through 3. You may have guessed it already, but these functions will no longer work. According to the error R is providing, we can only multiply data frames of the same size. R has done element-wise multiplication on the data frames. If we try this again with the order of the data frames reversed, we will get the same answer.

Hopefully this shed more light onto the way R performs multiplication, especially based on the data type. Like Like. Hope this helps!!! How can one make column-wise multiplications so that missing values are included na. I have tried prod, v1, v2, na. Thank you. If you were multiplying two values and one of them was NA, you would get NA as your answer.

Ignoring NAs would provide little benefit. However, if you use a function like applywhich allows you to sum or average across rows or columns, you can use the call na. Hope this helps!

Actually, if you use the apply function then you can do this. You are commenting using your WordPress. You are commenting using your Google account. You are commenting using your Twitter account.

How to multiply two columns in excel?

Notify me of new comments via email. Notify me of new posts via email. Standard Posted by wszafranski. Posted on July 28, Posted under data analysisR. Comments 5 Comments. This doesn't work. Incorrect dimensions. The output  "data. Error in Ops. Like this: Like LoadingSearch everywhere only in this topic. Advanced Search. Classic List Threaded.

It basically cannot be used to do computations, since in complicated matrix algebras, you have to distinguish where is scalar, and scalars obtained from quadratics cannot be directly used to multiply another matrix, etc. It is going to a huge mess Any thoughts? Re: how to multiply a constant to a matrix? Tony Plate I still can't see why this is a problem. If a 1x1 matrix should be treated as a scalar, then it can just be wrapped in dropand the arithmetic will be computed correctly by R.

Are there any cases where this cannot be done? More specifically, are there any matrix algebra expressions where, depending on the particular dimensions of the variables used, drop must be used in some cases, and not in other cases? A related but different behavior is the default dropping dimensions with extent equal to one by indexing operations. This can be problematic because if one is not careful, incorrect results can be obtained for particular values used in the expression. For example, consider the following, in which we are trying to compute the cross product of some columns of x with some rows of y.

If x has n rows and y has n columns, then the result should always be an nxn matrix. Martin Maechler. In reply to this post by LosemindL.

Search everywhere only in this topic Advanced Search how to multiply a constant to a matrix? Free forum by Nabble. Edit this page.This is a basic post about multiplication operations in R. This is where the elements in the same row are multiplied by one another. It will have the same number of rows as the first matrix x has 1 row and the same number of columns as the second matrix c has 2 columns. The previous operations were done using the default R arrays, which are matrices.

We can confirm this using the command class and typeof below:. Remember data frames in R can hold different types of data numbers, letters, etc. Note that there is an extra column of numbers from 1 to 3 for both c1 and x1. This is just a feature of the data frame output in R, where it is counting the rows 1 through 3. You may have guessed it already, but these functions will no longer work. According to the error R is providing, we can only multiply data frames of the same size.

R has done element-wise multiplication on the data frames. If we try this again with the order of the data frames reversed, we will get the same answer. Hopefully this shed more light onto the way R performs multiplication, especially based on the data type.

Standard Posted by wszafranski. Posted on July 28, Posted under data analysisR. Comments 5 Comments. This doesn't work. Incorrect dimensions. The output  "data. Error in Ops. Like this: Like Loading By continuing to use this website, you agree to their use. To find out more, including how to control cookies, see here: Cookie Policy.So now, I would suggest you to split the data frame into 2 parts and then multiply them. Just in case if you're columns are not sorted according to their names.

You can sort them by using order as follows:. Yes there are so many ways: df[,c V2,V4 ] and another Suppose your DataFrame is named as df: write. You need not spread twice, if you You can use dplyr function arrange like Can we create a alist as below You can parse the strings to symbols.

Related Questions In Data Analytics. How to replace NA values in a dataframe with Zero's? How to extract specific columns from a DataFrame? How to convert a list of dataframes in to a single dataframe using R? How to save a DataFrame in R?? How to achieve pivot like data using tidyverse library in R? How to sort a data frame by columns in R? How to remove NA values with dplyr::filter Can we create a alist as below How to use a function to repeat a set of procedures on specific set of columns in a data frame?

How to limit output of a dataframe in R? Welcome back to the World's most active Tech Community! Please enter a valid emailid. Forgot Password? Subscribe to our Newsletter, and get personalized recommendations. Sign up with Google Signup with Facebook Already have an account?Microsoft Excel is primarily designed to manipulate numbers, so it provides a handful of different ways to perform basic math operations as well as more complex calculations. In our last tutorial, we discussed how to multiply cells in Excel.

In this tutorial, we will take a step further and look at how you can quickly multiply entire columns. As is the case with all basic math operations, there is more than one way to multiply columns in Excel. Below, we will show you three possible solutions so you can choose the one that works best for you.

Here's how:.

### How to multiply columns in Excel

Supposing, your data begins in row 2, with B and C being the columns to be multiplied. If you prefer working with Excel functions rather than expressions, you can multiply 2 columns by using the PRODUCT function, which is a specially designed to do multiplication in Excel.

As with the multiply symbol, the key point is using relative cell references, so that the formula can adjust properly for each row. You enter the formula in the first cell, and then copy it down the column as explained in the above example:. One more way to multiply entire columns in Excel is by using an array formula. Please don't feel discouraged or intimidated by the words "array formula". This one is very straightforward and easy to use.

You simply write down the ranges you want to multiply separated by the multiplication sign, like this:. As the result, Excel will multiply a value in column B by a value in column C in each row, without you having to copy the formula down.

This approach might be useful if you want to prevent accidental deletion or alteration of the formula in individual cells. When such an attempt is made, Excel will show a warning that you cannot change part of an array.

## how to multiply a constant to a matrix?

To multiply more than two columns in Excel, you can use the multiplication formulas similar to the ones discussed above, but include several cells or ranges. As shown in the screenshot below, the formulas multiply numbers and percentages equally well. In situations when you want to multiply all values in a column by the same number, proceed in one of the following ways. Here's what you do:. In this example, we are going to multiply a column of numbers by percentage. In our sample table, the numbers to be multiplied are in column B beginning in row 4, so the formula goes as follows:. Double-click the small green square in the lower-right corner of the formula cell to copy the formula down the column as far as there is any data to the left.

That's it! You use a relative cell reference like B4 for the topmost cell in the column, so that this reference changes based on the relative position of a cell where the formula is copied.

Or, right-click the selection, choose Paste Special Either way, Excel will multiply each number in the range C4:C7 by the value in B1 and return the results as values, not formulas:. Like Paste Special, this multiplication method returns values rather than formulas.

Here's how you can multiply a column of numbers by another number in a couple of clicks:. For this, we copy the sales values from column B to column C, and then either:. Both methods do multiplication right and produce identical results:. Unlike Excel's Paste Special feature, the Ultimate Suite retains the original Currency format, so no further adjustments to the results are required. If you are curious to try Ultimate Suite's calculation options in your worksheets, you are welcome to download day trial version.

To have a closer look at the formulas discussed in this tutorial, feel free to download our sample Excel Multiply Columns workbook.Microsoft Excel is primarily designed to manipulate numbers, so it provides a handful of different ways to perform basic math operations as well as more complex calculations.

In our last tutorial, we discussed how to multiply cells in Excel. In this tutorial, we will take a step further and look at how you can quickly multiply entire columns.

As is the case with all basic math operations, there is more than one way to multiply columns in Excel. Below, we will show you three possible solutions so you can choose the one that works best for you.

Here's how:. Supposing, your data begins in row 2, with B and C being the columns to be multiplied. If you prefer working with Excel functions rather than expressions, you can multiply 2 columns by using the PRODUCT function, which is a specially designed to do multiplication in Excel. As with the multiply symbol, the key point is using relative cell references, so that the formula can adjust properly for each row.

You enter the formula in the first cell, and then copy it down the column as explained in the above example:. One more way to multiply entire columns in Excel is by using an array formula. Please don't feel discouraged or intimidated by the words "array formula". This one is very straightforward and easy to use.

You simply write down the ranges you want to multiply separated by the multiplication sign, like this:. As the result, Excel will multiply a value in column B by a value in column C in each row, without you having to copy the formula down. This approach might be useful if you want to prevent accidental deletion or alteration of the formula in individual cells.

When such an attempt is made, Excel will show a warning that you cannot change part of an array. To multiply more than two columns in Excel, you can use the multiplication formulas similar to the ones discussed above, but include several cells or ranges. As shown in the screenshot below, the formulas multiply numbers and percentages equally well. In situations when you want to multiply all values in a column by the same number, proceed in one of the following ways.

Here's what you do:. In this example, we are going to multiply a column of numbers by percentage. In our sample table, the numbers to be multiplied are in column B beginning in row 4, so the formula goes as follows:. Double-click the small green square in the lower-right corner of the formula cell to copy the formula down the column as far as there is any data to the left.

That's it!