hello1-i'm going to work with colash data following nested spatial model that in statistical method for spatial data analysis (oliver_schabben berger page150) .i devided data to 3 subgroups.i have fitted varigram model to every 3 subgroup. and also i have calculated covarianc matrix of them. but this matrixs havn't same dimention .and i coud not caculate $(4.23) of this page. what can i do ?
2-I have regular lattic data (wheat_yield ,page 434 of cerssi 1993, statistic for spatial data) when i have calculated the kriging ,unfortunatly the covariance matrix is 0 i'm going to work following method on the book for this data .what can i do?thank's in advance for your help and time.