# cumprod_byname: Cumulative element-product that respects row and column names In matsbyname: An Implementation of Matrix Mathematics

 cumprod_byname R Documentation

## Cumulative element-product that respects row and column names

### Description

Provides cumulative element-products along a list or column of a data frame. If `a` is a single number, `a` is returned. If `a` is a list of numbers, a list representing the cumulative product of the numbers is returned. If `a` is a single matrix, `a` is returned. If `a` is a list of matrices, a list representing the cumulative product of the matrices is returned. In this case, each entry in the returned list is product "by name," such that row and column names of the matrices are respected.

### Usage

```cumprod_byname(a)
```

### Arguments

 `a` a number, list of numbers, matrix or list of matrices for which cumulative element product is desired

### Details

This function respects groups if `a` is a variable in a data frame.

### Value

a single number, list of numbers, a single matrix, or a list of matrices, depending on the nature of `a`

### Examples

```cumprod_byname(list(1, 2, 3, 4, 5))
m1 <- matrix(c(1), nrow = 1, ncol = 1, dimnames = list("r1", "c1")) %>%
setrowtype("row") %>% setcoltype("col")
m2 <- matrix(c(2), nrow = 1, ncol = 1, dimnames = list("r2", "c2")) %>%
setrowtype("row") %>% setcoltype("col")
m3 <- matrix(c(3), nrow = 1, ncol = 1, dimnames = list("r3", "c3")) %>%
setrowtype("row") %>% setcoltype("col")
cumprod_byname(list(m1, m2, m3))
```

matsbyname documentation built on April 2, 2022, 1:06 a.m.