dont know how to make the graph of poisson distribution

[rahul67]

I m trying to make this figure but getting an error. can some body help me what is my mistake.

below is my code

library("ggplot2")
library(plotly)
x.values <- seq(0, 20, 1)
break.values <- seq(0, 20, 2)
zeros11 <- rep(0, 11)
y1 <- dpois(x.values, 9)
y2 <- dpois(x.values, 5)
df2 <- data.frame(x.values, y1)
y <- ggplot(df2, aes(x=x.values, y=y1))+
geom_bar(stat="identity", width = 0.5)+labs(x = "x-Werte", y = "Werte Poissonverteilungen")+
scale_x_continuous(breaks=break.values, labels=break.values)

[williaml]

Edited. This should work.

As mentioned by @FJCC below, you didn't call y. I imagine that you wanted to put it in to a plotly object which is why you have called the library.

library(tidyverse)
library(plotly)
x.values <- seq(0, 20, 1)
break.values <- seq(0, 20, 2)
y1 <- dpois(x.values, 9)
y2 <- dpois(x.values, 5)
y3 <- dpois(x.values, 1)
df3 <- data.frame(x.values, y1, y2, y3) %>% 
  pivot_longer(-x.values, names_to = "lambda", values_to = "values") %>% 
  mutate(lambda = case_when(lambda == "y1" ~ "lambda = 5",
                            lambda == 'y2' ~ "lambda = 9",
                            lambda == 'y3' ~ "lambda = 1",
                            TRUE ~ NA_character_))

g <- ggplot(df3, aes(x.values, y = values, fill = lambda)) +
  geom_col(position = "dodge") +
  labs(x = "x-Werte", y = "Werte Poissonverteilungen", fill = NULL) +
  scale_x_continuous(breaks=break.values, labels=break.values)

ggplotly(g)

  

[FJCC]

The posted code works to make the plot when lambda = 9 if I append a final call of y to print out the graph

library("ggplot2")
library(plotly)
#> 
#> Attaching package: 'plotly'
#> The following object is masked from 'package:ggplot2':
#> 
#>     last_plot
#> The following object is masked from 'package:stats':
#> 
#>     filter
#> The following object is masked from 'package:graphics':
#> 
#>     layout
x.values <- seq(0, 20, 1)
break.values <- seq(0, 20, 2)
zeros11 <- rep(0, 11)
y1 <- dpois(x.values, 9)
y2 <- dpois(x.values, 5)
df2 <- data.frame(x.values, y1)
y <- ggplot(df2, aes(x=x.values, y=y1))+
  geom_bar(stat="identity", width = 0.5)+labs(x = "x-Werte", y = "Werte Poissonverteilungen")+
  scale_x_continuous(breaks=break.values, labels=break.values)
y

^{Created on 2020-02-13 by the reprex package (v0.2.1)}

[rahul67]

trying to use pivot_longer but showing error. Is there any package for pivot_longer?

[williaml]

pivot_longer is in tidyr which is part of the tidyverse.

Pivot data from wide to long — pivot_longer

[rahul67]

using pivot_longer with tidyverse package but showing error.

[williaml]

You might need to update tidyr as pivot_longer is fairly new.

[rahul67]

It is not working after updating the packages. It is still showing error.

[williaml]

Maybe it needs a restart?

Anyway, try this. It uses gather instead:

library(tidyverse)
library(plotly)
x.values <- seq(0, 20, 1)
break.values <- seq(0, 20, 2)
y1 <- dpois(x.values, 9)
y2 <- dpois(x.values, 5)
y3 <- dpois(x.values, 1)

data.frame(x.values, y1, y2, y3) %>% 
  gather(-x.values, key = "lambda", value = "values") %>% 
  mutate(lambda = case_when(lambda == "y1" ~ "lambda = 5",
                            lambda == 'y2' ~ "lambda = 9",
                            lambda == 'y3' ~ "lambda = 1",
                            TRUE ~ NA_character_))

g <- ggplot(df3, aes(x.values, y = values, fill = lambda)) +
  geom_col(position = "dodge") +
  labs(x = "x-Werte", y = "Werte Poissonverteilungen", fill = NULL) +
  scale_x_continuous(breaks=break.values, labels=break.values)

ggplotly(g)

[rahul67]

@williaml

gather

Thankyou for your help. Really appreciate it.

[nirgrahamuk]

Williammmm, now we'll never know what the pivot_longer error was !