I am looking to create a PCF that provides the correlation coefficient (r²) of a 60 period linear regression. The aim is to use the value to help determine the quality of the slope of the linear regression line.

Any help would be much appreciated.

Please try the following Indicator Formula for the 60-Period R-Squared:

((((60 - 1) / 2) * AVGC60 - (C1 + 2 * C2 + 3 * C3 + 4 * C4 + 5 * C5 + 6 * C6 + 7 * C7 + 8 * C8 + 9 * C9 + 10 * C10 + 11 * C11 + 12 * C12 + 13 * C13 + 14 * C14 + 15 * C15 + 16 * C16 + 17 * C17 + 18 * C18 + 19 * C19 + 20 * C20 + 21 * C21 + 22 * C22 + 23 * C23 + 24 * C24 + 25 * C25 + 26 * C26 + 27 * C27 + 28 * C28 + 29 * C29 + 30 * C30 + 31 * C31 + 32 * C32 + 33 * C33 + 34 * C34 + 35 * C35 + 36 * C36 + 37 * C37 + 38 * C38 + 39 * C39 + 40 * C40 + 41 * C41 + 42 * C42 + 43 * C43 + 44 * C44 + 45 * C45 + 46 * C46 + 47 * C47 + 48 * C48 + 49 * C49 + 50 * C50 + 51 * C51 + 52 * C52 + 53 * C53 + 54 * C54 + 55 * C55 + 56 * C56 + 57 * C57 + 58 * C58 + 59 * C59) / 60) / SQR(((60 ^ 2 - 1) / 12) * ((C ^ 2 + C1 ^ 2 + C2 ^ 2 + C3 ^ 2 + C4 ^ 2 + C5 ^ 2 + C6 ^ 2 + C7 ^ 2 + C8 ^ 2 + C9 ^ 2 + C10 ^ 2 + C11 ^ 2 + C12 ^ 2 + C13 ^ 2 + C14 ^ 2 + C15 ^ 2 + C16 ^ 2 + C17 ^ 2 + C18 ^ 2 + C19 ^ 2 + C20 ^ 2 + C21 ^ 2 + C22 ^ 2 + C23 ^ 2 + C24 ^ 2 + C25 ^ 2 + C26 ^ 2 + C27 ^ 2 + C28 ^ 2 + C29 ^ 2 + C30 ^ 2 + C31 ^ 2 + C32 ^ 2 + C33 ^ 2 + C34 ^ 2 + C35 ^ 2 + C36 ^ 2 + C37 ^ 2 + C38 ^ 2 + C39 ^ 2 + C40 ^ 2 + C41 ^ 2 + C42 ^ 2 + C43 ^ 2 + C44 ^ 2 + C45 ^ 2 + C46 ^ 2 + C47 ^ 2 + C48 ^ 2 + C49 ^ 2 + C50 ^ 2 + C51 ^ 2 + C52 ^ 2 + C53 ^ 2 + C54 ^ 2 + C55 ^ 2 + C56 ^ 2 + C57 ^ 2 + C58 ^ 2 + C59 ^ 2) / 60 - AVGC60 ^ 2))) ^ 2

Need help writing a PCF for r-squared