R/CI.RMSEA.R

In GAIPE: Graphical Extension with Accuracy in Parameter Estimation (GAIPE)

CI.RMSEA=function(rmsea,df,N,clevel=.95){
  if (length(rmsea) != 1 | rmsea < 0) {
    stop("rmsea has to be correctly specified.")
  }
  if (length(df) != 1 | df <= 0) {
    stop("df has to be correctly specified.")
  }
  if (length(N) != 1 | N <= 0) {
    stop("N has to be correctly specified.")
  }
  if (length(clevel) != 1 | clevel <= 0 | clevel >= 1) {
    stop("clevel has to be correctly specified.")
  }
  tol = 0.0000001
  T = rmsea^2 * df * (N - 1) + df
  C = qchisq(1 - (1 - clevel)/2, df)
  if ((T < C | rmsea == 0) & N > 1) {
    start = rmsea
    O_U_P = (1 - clevel)/2
    P_LU = 1
    A = c(0.01, 0.001, 0.0001, 0.00001, 0.000001, 0.0000001)
    for (i in c(1, 3, 5)) {
      while (P_LU > O_U_P) {
        P_LU = pchisq(T, df, start^2 * df * (N - 1))
        if (P_LU > O_U_P) {
          start = start + A[i]
        }
      }
      while (P_LU < O_U_P) {
        P_LU = pchisq(T, df, start^2 * df * (N - 1))
        if (P_LU < O_U_P) {
          start = start - A[i + 1]
        }
        if (start < 0) {
          start = 0
        }
      }
    }
    k = 0
    while (abs(P_LU - O_U_P) > tol & k < 20) {
      P_LU = pchisq(T, df, start^2 * df * (N - 1))
      if (P_LU > O_U_P) {
        start = start + 0.00000001
      }
      if (P_LU < O_U_P) {
        start = start - 0.00000001
      }
      k = k + 1
      if (start < 0) {
        start = 0
      }
    }
    if (k == 20) {
      start1 = start
      start2 = start + 0.00000001
      s1 = pchisq(T, df, start1^2 * df * (N - 1))
      s2 = pchisq(T, df, start2^2 * df * (N - 1))
      start = c(start1, start2)[which((abs(c(s1, s2) - 
                                             O_U_P)) == min(abs(c(s1, s2) - O_U_P)))]
    }
    L.rmsea = 0
    U.rmsea = start
  }
  if (T > C & N > 1) {
    O_U_P = (1 - clevel)/2
    P_LU = 1
    start = rmsea
    A = c(0.01, 0.001, 0.0001, 0.00001, 0.000001, 0.0000001)
    for (i in c(1, 3, 5)) {
      while (P_LU > O_U_P) {
        P_LU = pchisq(T, df, start^2 * df * (N - 1))
        if (P_LU > O_U_P) {
          start = start + A[i]
        }
      }
      while (P_LU < O_U_P) {
        P_LU = pchisq(T, df, start^2 * df * (N - 1))
        if (P_LU < O_U_P) {
          start = start - A[i + 1]
        }
        if (start < 0) {
          start = 0
        }
      }
    }
    k = 0
    while (abs(P_LU - O_U_P) > tol & k < 20) {
      P_LU = pchisq(T, df, start^2 * df * (N - 1))
      if (P_LU > O_U_P) {
        start = start + 0.00000001
      }
      if (P_LU < O_U_P) {
        start = start - 0.00000001
      }
      k = k + 1
      if (start < 0) {
        start = 0
      }
    }
    if (k == 20) {
      start1 = start
      start2 = start + 0.00000001
      s1 = pchisq(T, df, start1^2 * df * (N - 1))
      s2 = pchisq(T, df, start2^2 * df * (N - 1))
      start = c(start1, start2)[which((abs(c(s1, s2) - 
                                             O_U_P)) == min(abs(c(s1, s2) - O_U_P)))]
    }
    U.rmsea = start
    start = 0
    O_L_P = 1 - (1 - clevel)/2
    P_LL = 1
    A = c(0.01, 0.001, 0.0001, 0.00001, 0.000001, 0.0000001)
    for (i in c(1, 3, 5)) {
      while (P_LL > O_L_P) {
        P_LL = pchisq(T, df, start^2 * df * (N - 1))
        if (P_LL > O_L_P) {
          start = start + A[i]
        }
      }
      while (P_LL < O_L_P) {
        P_LL = pchisq(T, df, start^2 * df * (N - 1))
        if (P_LL < O_L_P) {
          start = start - A[i + 1]
        }
        if (start < 0) {
          start = 0
        }
      }
    }
    k = 0
    while (abs(P_LL - O_L_P) > tol & k < 20) {
      P_LL = pchisq(T, df, start^2 * df * (N - 1))
      if (P_LL > O_L_P) {
        start = start + 0.00000001
      }
      if (P_LL < O_L_P) {
        start = start - 0.00000001
      }
      k = k + 1
      if (start < 0) {
        start = 0
      }
    }
    if (k == 20) {
      start1 = start
      start2 = start + 0.00000001
      s1 = pchisq(T, df, start1^2 * df * (N - 1))
      s2 = pchisq(T, df, start2^2 * df * (N - 1))
      start = c(start1, start2)[which((abs(c(s1, s2) - 
                                             O_U_P)) == min(abs(c(s1, s2) - O_U_P)))]
    }
    L.rmsea = start
  }
  if (N == 1) {
    L.rmsea = 0
    U.rmsea = Inf
  }
  list(Lower.CI = L.rmsea, RMSEA = rmsea, Upper.CI = U.rmsea)
}