Let’s pretend we don’t know the length of my_seq, but we want to generate a sequence of integers from 1 to N, where N represents the length of the my_seq vector. To do this, you need to include the object ‘my_seq’ as the value of argument ‘x’ of length(). To confirm that my_seq has length 30, we can use the length() function. You can actually use any abbreviation of the argument name, as long as it is different from any other argument. If you look closely again at the help file for ?seq, you will not see an argument “length =”, but only “length.out =”. Give it a shot now and store the result in a new variable called my_seq. Or maybe we don’t care what the increment is and we just want a sequence of 30 numbers between 5 and 10. OK, let’s say that instead of 1 to 20, we want a vector of numbers ranging from 0 to 10, incremented by 0.5. However, for complex functions it is often best practice to do so and makes your code much clearer.įor example, seq(from = 1, to = 20) will give the same output as seq(1, 20). In R, you do not have to specify the arguments by name if you write out their values in the same order as written in the function. The first two arguments are “from =” and “to =”. The help files show the arguments listed for the seq() function. The most basic use of seq() does exactly the same thing as the : operator. Often, we’ll desire more control over a sequence we’re creating than what the : operator gives us. If you don’t have a backtick key, you can use regular quotes.) (NOTE: The backtick (`) key is generally located in the top left corner of a keyboard, above the Tab key. However, in the case of an operator like the colon used above, you must enclose the symbol in backticks like this: ?. Remember that if you have questions about a particular R function, you can access its documentation with a question mark followed by the function name: ?function_name_here. It counted backwards in increments of 1! This is sometimes useful for plotting coefficients from models in reverse order. What happens if we do 15:1? Give it a try to find out. Note also that pi is one of the few constants built in to R. The upper limit of 10 is never reached, since the next number in our sequence would be greater than 10. The result is a vector of real numbers starting with pi (3.142…) and increasing in increments of 1. We could also use it to create a sequence of real numbers (a real number is a positive, negative, or 0 with an infinite or finite sequence of digits after the decimal place). That gave us every integer between (and including) 1 and 20 (an integer is a positive or negative counting number, including 0). The simplest way to create a sequence of numbers in R is by using the : operator. Sequences of numbers are used in many different tasks, from plotting the axes of graphs to generating simulated data. So please adjust as necessary.In this lesson, you’ll learn how to create sequences of numbers in R. Note that I have not included the multiplication of the returned value by the constant (at the end of your function) as this was not in your description of the desired result. This will mean the formula is treated as an array formula and will return a single value. If you have an earlier version of Excel, you can still achieve the same result as option 2 but you need to press Ctrl+ Shift+ Enter at the end of typing the function instead of just Enter. This is my preferred option as it doesn't require the helper column S.Ĭell X14: If you have a recent version of Excel 365, you can use dynamic arrays in the IF function, and use the formula displayed in cell Y10, which I've used in X10. You could calculate the whether the condition is met for each row (as in column S) then use the formula displayed in cell Y2 that I've used in cell X2. To make the screenshot narrower, I have mine in V3. The way I understand this, you have your constant in cell AN36. See the array starting on U5 and spilling downward. Unfortunately it seems that multiplying a range by a constant in the criteria of SUMIF results in an array instead of a single number.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |