Update README.md

Author: taehyounpark

README.md

@@ -42,21 +42,19 @@ int main() {
   dataflow df(multithread::enable(10));
 
   std::ifstream data("data.json");
-  auto [x, v, w] = df.read(
-      dataset::input<json>(data), dataset::column<double>("x"),
-      dataset::column<std::vector<double>>("v"), dataset::column<double>("w"));
+  auto [x, w] = df.read(
+      dataset::input<json>(data), dataset::column<std::vector<double>>("x"), dataset::column<double>("w"));
 
   auto zero = df.define(column::constant(0));
-  auto v0 = v[zero];
+  auto x0 = x[zero];
 
   auto sel =
       df.weight(w)
           .filter(column::expression(
-              [](std::vector<double> const &v) { return v.size(); }))(v)
-          .filter(column::expression([](double x) { return x > 100.0; }))(x);
+              [](std::vector<double> const &v) { return v.size(); }))(v);
 
   auto h_x0_w = df.get(query::output<h1d>(linax(20, 0.0, 200.0)))
-                    .fill(v0)
+                    .fill(x0)
                     .at(sel)
                     .result();