gsl-shell.git - gsl-shell

diff --git a/expr-print.lua b/expr-print.lua
index 0520d776..a14d400c 100644
--- a/expr-print.lua
+++ b/expr-print.lua

@@ -1,4 +1,5 @@

local expr_lexer = require 'expr-lexer'

+local AST = require 'expr-actions'

local format, concat = string.format, table.concat

@@ -108,8 +109,9 @@ end

local function ref_list_rec(expr, list)

if type(expr) == 'number' then

return

- elseif type(expr) == 'string' then

- list[expr] = true

+ elseif AST.is_variable(expr) then

+ local _, var_name = AST.is_variable(expr)

+ list[var_name] = true

elseif expr.literal then

return

elseif expr.func then

diff --git a/gdt-lm.lua b/gdt-lm.lua
index 31e26fe4..f14bdf46 100644
--- a/gdt-lm.lua
+++ b/gdt-lm.lua

@@ -169,9 +169,27 @@ function FIT.eval(fit, tn)

return sy

end

+local function check_var_references(t, schema)

+ local refs = {}

+ for _, expr in ipairs(schema.x) do

+ expr_print.references(expr, refs)

+ end

+ expr_print.references(schema.y, refs)

+ for _, expr in ipairs(schema.conds) do

+ expr_print.references(expr, refs)

+ end

+ for var_name in pairs(refs) do

+ if not t:col_index(var_name) then

+ error('invalid reference to column name \"'..var_name.."\"", 3)

+ end

+ end

+end

+

local function lm(t, model_formula, options)

local schema = expr_parse.schema(model_formula, AST, false)

+ check_var_references(t, schema)

+

local expand = not options or (options.expand == nil or options.expand)

local xs = expand and expand_exprs(schema.x) or schema.x

local x_exprs = gdt_factors.compute(t, xs)