I keep getting NA for the code below to find the sum of vector in R without using sum():
total <- 0
for ()) {
add = gg[n] + gg[n+1]
total = total + add
}
Your getting a NA because gg[n+1] does not exist when last step (length(gg)) : so it finally adds NA to your sum.
Use for (n in (1:(length(gg)-1)) ) instead
(and tip to debug : print the contents of your variables at each steps using print() - launch code below to see your issue :
total <- 0
for (n in (1:length(gg)) ) {
print(paste("n: ",n))
print(paste("gg for n : ",gg[n], "and n+1: ",gg[n+1]))
add = gg[n] + gg[n+1]
print(paste("add when loop = ", n, ":", add))
total = total + add
print(total)
}
total
Related
I would like to calculate RSI 14 in line with the tradingview chart.
According to there wiki this should be the solution:
https://www.tradingview.com/wiki/Talk:Relative_Strength_Index_(RSI)
I implemented this is in a object called RSI:
Calling within object RSI:
self.df['rsi1'] = self.calculate_RSI_method_1(self.df, period=self.period)
Implementation of the code the calculation:
def calculate_RSI_method_1(self, ohlc: pd.DataFrame, period: int = 14) -> pd.Series:
delta = ohlc["close"].diff()
ohlc['up'] = delta.copy()
ohlc['down'] = delta.copy()
ohlc['up'] = pd.to_numeric(ohlc['up'])
ohlc['down'] = pd.to_numeric(ohlc['down'])
ohlc['up'][ohlc['up'] < 0] = 0
ohlc['down'][ohlc['down'] > 0] = 0
# This one below is not correct, but why?
ohlc['_gain'] = ohlc['up'].ewm(com=(period - 1), min_periods=period).mean()
ohlc['_loss'] = ohlc['down'].abs().ewm(com=(period - 1), min_periods=period).mean()
ohlc['RS`'] = ohlc['_gain']/ohlc['_loss']
ohlc['rsi'] = pd.Series(100 - (100 / (1 + ohlc['RS`'])))
self.currentvalue = round(self.df['rsi'].iloc[-1], 8)
print (self.currentvalue)
self.exportspreadsheetfordebugging(ohlc, 'calculate_RSI_method_1', self.symbol)
I tested several other solution like e.g but non return a good value:
https://github.com/peerchemist/finta
https://gist.github.com/jmoz/1f93b264650376131ed65875782df386
Therefore I created a unittest based on :
https://school.stockcharts.com/doku.php?id=technical_indicators:relative_strength_index_rsi
I created an input file: (See excel image below)
and a output file: (See excel image below)
Running the unittest (unittest code not included here) should result in but is only checking the last value.
if result == 37.77295211:
log.info("Unit test 001 - PASSED")
return True
else:
log.error("Unit test 001 - NOT PASSED")
return False
But again I cannot pass the test.
I checked all values by help with excel.
So now i'm a little bit lost.
If I'm following this question:
Calculate RSI indicator from pandas DataFrame?
But this will not give any value in the gain.
a) How should the calculation be in order to align the unittest?
b) How should the calculation be in order to align with tradingview?
Here is a Python implementation of the current RSI indicator version in TradingView:
https://github.com/lukaszbinden/rsi_tradingview/blob/main/rsi.py
I had same issue in calculating RSI and the result was different from TradingView,
I have found RSI Step 2 formula described in InvestoPedia and I changed the code as below:
N = 14
close_price0 = float(klines[0][4])
gain_avg0 = loss_avg0 = close_price0
for kline in klines[1:]:
close_price = float(kline[4])
if close_price > close_price0:
gain = close_price - close_price0
loss = 0
else:
gain = 0
loss = close_price0 - close_price
close_price0 = close_price
gain_avg = (gain_avg0 * (N - 1) + gain) / N
loss_avg = (loss_avg0 * (N - 1) + loss) / N
rsi = 100 - 100 / (1 + gain_avg / loss_avg)
gain_avg0 = gain_avg
loss_avg0 = loss_avg
N is the number of period for calculating RSI (by default = 14)
the code is put in a loop to calculate all RSI values for a series.
For those who are experience the same.
My raw data contained ticks where the volume is zero. Filtering this OLHCV rows will directly give the good results.
I want to calculate the difference of two columns of a dataframe containing times. Since not always a value from the same column ist bigger/later, I have to do a workaround with an if-clause:
counter = 1
while(counter <= nrow(data)){
if(data$time_end[counter] - data$time_begin[counter] < 0){
data$chargingDuration[counter] = 1-abs(data$time_end[counter]-data$time_begin[counter])
}
if(data$time_end[counter] - data$time_begin[counter] > 0){
data$chargingDuration[counter] = data$time_end[counter]-data$time_begin[counter]
}
counter = counter + 1
}
The output I get is a decimalvalue smaller than 1 (i.e.: 0,53322 meaning half a day)... However, if I use my console and calculate the timedifference manually for a single line, I get my desired result looking like 02:12:03...
Thanks for the help guys :)
I am new to using R and have minimal amount of Python experience. I am sure this is an easy fix but I am just not seeing it. I was given a code to run a Fibonacci sequence to 100 and I copy and pasted it, but I am getting the following error code: Error in if (numterms <= 0) { : missing value where TRUE/FALSE needed. I know this has to do with the if/else clause but I am not seeing the problem.
I have run through the code a couple different ways but it has not helped. And the person to assist is not available during the weekend. Any help would be appreciated.
# take the max number input from the user
numterms = as.integer(readline(prompt="What is your max number? "))
# first two items
num1 = 0
num2 = 1
counter = 2
# check if the number of terms is valid
if(numterms <= 0) {
print("Please enter an integer above zero")
} else {
if(numterms == 1) {
print("The Fibonacci sequence:")
print(num1)
} else {
print("The Fibonacci sequence:")
print(num1)
print(num2)
while(counter < numterms) {
numth = num1 + num2
print(numth)
# update values
num1 = num2
num2 = numth
counter = counter + 1
}
}
}
If you just execute the code numterms is not correctly defined. It is normally defined by a user input: The function readline reads the numbers the user types in the command line. If you just execute this line you can properly define numterms.
If you execute all the code at once numterms is set to NA which cannot be compared to 0 in the numterms <= 0 clause. In this case numterms <= 0 is also NA which is not a logical value and can therefore not be evaluated by if. This ultimately causes your error.
The solution would be to just run the first line of your code and enter the number and only after you entered the number to execute the rest of the code.
Alternatively you can define your code as a function:
printFibonacci <- function(){
numterms = as.integer(readline(prompt="What is your max number? "))
if(is.na(numterms)){
numterms <- 4
}
# first two items
num1 = 0
num2 = 1
counter = 2
# check if the number of terms is valid
if(numterms <= 0) {
print("Please enter an integer above zero")
} else {
if(numterms == 1) {
print("The Fibonacci sequence:")
print(num1)
} else {
print("The Fibonacci sequence:")
print(num1)
print(num2)
while(counter < numterms) {
numth = num1 + num2
print(numth)
# update values
num1 = num2
num2 = numth
counter = counter + 1
}
}
}
}
And then just call your function with printFibonacci(). In this case the prompt and answer of the readline function gets executed first and numterms can be defined by the user before the rest of the code is executed.
I would like to find the value of "p" below (which is between 0 and 1), knowing the following equations:
RI_26 = min(IR,na.rm=FALSE)
RI_min = 100-(sse*SUM/((1+p)*Dotation2017*100))^(1/p)
where RI_26 is the minimum of resources index of my 26 area. It is a constant in my case. In RI_min, sse and Dotations2017 are 2 constants and p is a unknown. I know that RI_26 should be equal to RI_min.
It would be easy to solve it, but SUM (which is present in RI_min) is as well unknown as it is a function of p as following:
`sum.function = function(p){
SUM <- c(0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)
for(i in 1:length(Canton))
if(IR[i] < 100) {
SUM[i] <- (100-IR[i])^(1+p)*Pop[i]
SUM[27] <- SUM[27]+SUM[i]
}
SUM <- round(SUM,0)
return(SUM[27])
}
SUM = sum.function(p)
SUM returns a number (or vector 1X1). To deal with it, I would like to find the value of p that satisfied:
RI_26/RI_min = 1
To do so, I would like to do a loop, beginning with p = 0 and then increasing the value of p by 0.01 until it reaches 1. The loop should return the value of p_star when the constraint is True (RI_26/RI_min = 1.00).
I don't have any idea how to do this but it could look like the following code:
p.function = function(){
for(...)
if(RI_26/RI_min = 1.000000) {
p_star <- p
}
return(p_star)
}
So the function will return the value of p_star when RI_26/RI_min = 1.000000. What am I suppose to write in my function: p.function to increment "p" and have the result that I want? Any idea?
for (i in seq(0, 1, by = 0.1)) {
"Your code here"
}
got a while loop going, and that's working fine.
However I also need to add another condition.
I need the loop to keep going until it satisfies the while loop, but then I also need to add that this can only get repeated x times.
I think you would have to make a for loop to do x times, is it possible to put a while loop in this?
Basically how can I make a loop either reach the goal or stop after x loops??
The expression in while needs to be TRUE for the loop to continue. You can use | or & to add extra conditions. This loop runs 99 times or until sum of random variables is less than 100.
counter <- 0
result <- 0
while(counter < 100 | sum(result) < 100) {
result <- sum(result, rnorm(1, mean = 5, sd = 1))
counter <- sum(counter, 1)
}
> result
[1] 101.5264
> counter
[1] 21
Just pass the current iterator value as an argument to your function. That way you can break the recursion if that reaches a particular value.
But why do you have a while loop if you use recursion, for example:
add_one_recursive = function(number) {
number = number + 1
cat("New number = ", number, "\n")
if(number > 10) {
return(number)
} else {
return(add_one_recursive(number))
}
}
final_number = add_one_recursive(0)
New number = 1
New number = 2
New number = 3
New number = 4
New number = 5
New number = 6
New number = 7
New number = 8
New number = 9
New number = 10
New number = 11
Does not require an explicit loop at all.