Bt: Tindle method

Recalculation to 22 ox with F,Cl correction. Li2O and H2O calculations after Tindle and Webb (1990) European Journal of Mineralogy, vol. 2, pgs. 595-610.

recalc.bt_tindle <- function (wtp_data, ...)
{

base_names <- c('SiO2_wtp','TiO2_wtp','Al2O3_wtp','FeO_wtp','MnO_wtp','MgO_wtp','CaO_wtp','Na2O_wtp','K2O_wtp',
               'SrO_wtp','BaO_wtp','Rb2O_wtp','Cs2O_wtp','ZnO_wtp','SnO2_wtp','Ga2O3_wtp',
               'F_wtp','Cl_wtp','Cr2O3_wtp','NiO_wtp','CuO_wtp');

data <- selectNames(wtp_data,base_names);

data$Li2O_wtp  <- (0.287*data$SiO2_wtp)-9.552;
data$Li2O_wtp <- ifelse(data$Li2O_wtp<0,0,data$Li2O_wtp);

step1_coeff <- c(30.045,39.95,33.9867,71.85,70.94,40.31,56.08,61.98,94.22,
             103.62,153.36,186.936,281.811,81.38,75.345,62.48,
             19,35.45,50.6667,74.7,79.55,29.88);

step1_data <- rowApply(`/`, data, step1_coeff);
step1_sum <- rowSums(step1_data);
F_Cl_corr <- step1_sum - step1_data$F_wtp - step1_data$Cl_wtp;
Ox_Num <- 22/F_Cl_corr;

step2_data <- rowApply(`*`, step1_data, Ox_Num);

pfu_names <- c('Si_pfu','Ti_pfu','Al_pfu','Fe_pfu','Mn_pfu','Mg_pfu','Ca_pfu','Na_pfu','K_pfu',
               'Sr_pfu','Ba_pfu','Rb_pfu','Cs_pfu','Zn_pfu','Sn_pfu','Ga_pfu',
               'F_pfu','Cl_pfu','Cr_pfu','Ni_pfu','Cu_pfu','Li_pfu');

ox_norm <- c( 1/2,1/2,2/3,1/1,1/1,1/1,1/1,2/1,2/1,
              1/1,1/1,2/1,2/1,1/1,1/2,2/3,
              1,1,2/3,1/1,1/1,2/1);

step3_data <-  rowApply(`*`, step2_data, ox_norm) ;
names(step3_data) <- pfu_names;

step3_data$Al_c4_pfu <- ifelse(step3_data$Al_pfu > 8-step3_data$Si_pfu,8-step3_data$Si_pfu,step3_data$Al_pfu);
step3_data$Al_c4_pfu <- ifelse(step3_data$Si_pfu>8,0,step3_data$Al_c4_pfu);
step3_data$Al_c6_pfu <- ifelse(step3_data$Si_pfu+step3_data$Al_pfu<8,0,step3_data$Al_pfu-step3_data$Al_c4_pfu);

step3_data$ОН_pfu <- 4 - step3_data$F_pfu - step3_data$Cl_pfu;
step3_data$ОН_pfu <- ifelse(step3_data$ОН_pfu < 0, 0 , step3_data$ОН_pfu);

return(cbind(wtp_data$Name,step3_data));
}