[R] Relative Cumulative Frequency of Event Occurence

[arun]

HI,
From the dput() version of df.1, it looks like you want:
cumsum(df.1[,4]=="Yes")/seq_len(nrow(df.1))
 [1] 0.0000000 0.5000000 0.3333333 0.2500000 0.4000000 0.3333333 0.4285714
 [8] 0.5000000 0.4444444 0.5000000


A.K.


On Thursday, November 28, 2013 11:26 AM, Burhan ul haq <ulhaqz at gmail.com> wrote:
Hi,

My objective is to calculate "Relative (Cumulative) Frequency of Event
Occurrence" - something as follows:

Sample.Number 1st.Fly 2nd.Fly  Did.E.occur? Relative.Cum.Frequency.of.E
1 G B No 0.000
2 B B Yes 0.500
3 B G No 0.333
4 G B No 0.250
5 G G Yes 0.400
6 G B No 0.333
7 B B Yes 0.429
8 G G Yes 0.500
9 G B No 0.444
10 B B Yes 0.500

Please refer to the code below:
##############################################################
# 1.
v.fly=c("G","B") # Outcome is Green or Blue fly

# 2.
n=10 # No of Events / Trials

# 3.
v.smp = seq(1:n) # Event Id

# 4.
v.fst = sample(v.fly,n,rep=T) # Simulating First Draw

# 5.
v.sec = sample(v.fly,n,rep=T)  # Simulating Second Draw

# 6.
df.1 = data.frame(sample = v.smp, fst=v.fst, sec = v.sec) # Clumping in a DF

# 7.
df.1$E.Occur = with(df.1, ifelse(fst==sec,TRUE,FALSE)) # Event Occurs, if
color is same in both the the draws

# 8.
df.1$Rel.Freq = with(df.1, cumsum(E.occur)/(E.Occur)) # Relative Frequency
>> This line does NOT work, and needs to fix the denominator part
##############################################################

Problem is with #8, specifically the part:
cumsum(E.occur)/(E.Occur)

The denominator E.Occur is a fixed value, instead of a moving count. I have
tried nrow(), length() but none provides a moving version of row count, as
cumsum does for the "True" values, occurring so far.

> dput(df.1)
structure(list(Sample.Number = 1:10, X1st.Fly = c("G", "B", "B",
"G", "G", "G", "B", "G", "G", "B"), X2nd.Fly = c("B", "B", "G",
"B", "G", "B", "B", "G", "B", "B"), Did.E.occur. = c("No", "Yes",
"No", "No", "Yes", "No", "Yes", "Yes", "No", "Yes"),
Relative.Cum.Frequency.of.E = c(0,
0.5, 0.333, 0.25, 0.4, 0.333, 0.429, 0.5, 0.444, 0.5)), .Names =
c("Sample.Number",
"X1st.Fly", "X2nd.Fly", "Did.E.occur.", "Relative.Cum.Frequency.of.E"
), class = "data.frame", row.names = c(NA, -10L))


Cheers !

    [[alternative HTML version deleted]]

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