save results of loop in a vector R -


i run loop:

n = 10 alpha = 0.05 sigma = 0.01 (i in 0:n){ vt10[i] = ((sigma^2)/(alpha^2))*((n-i)+(2/alpha))*exp(-alpha*(n-i))-(1/(2*alpha))*exp(-2*alpha*(n-i))-(3/(2*alpha)) } 

however, vt10 outputs 10 outcomes (doesn't include first iteration, when i = 0). how can create vector include 11 iterations?

answer:

n = 10 alpha = 0.05 sigma = 0.01 vt10 = numeric(11)  ## this! (i in 0:n){ vt10[i+1] = ((sigma^2)/(alpha^2))*((n-i)+(2/alpha))*exp(-alpha*(n-i))-(1/(2*alpha))*exp(-2*alpha*(n-i))-(3/(2*alpha)) } 

also, need vt10[i+1], because loop 0 10, while array index should 1 11.


comment:

your code looks c code. not start index 0, write loop task.

try:

n = 10 alpha = 0.05 sigma = 0.01 = 0:10 vt10 = ((sigma^2)/(alpha^2))*((n-i)+(2/alpha))*exp(-alpha*(n-i))-(1/(2*alpha))*exp(-2*alpha*(n-i))-(3/(2*alpha)) 

in situation, there no need predefine vector. r knows performing element-wise computation, , automatically assign length-11 vector vt10.


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