From 620b996f2ffe5e9e426b88f57e4f46bc9af7f237 Mon Sep 17 00:00:00 2001
From: justanothercatgirl <sotov2070@gmail.com>
Date: Wed, 5 Mar 2025 20:12:26 +0300
Subject: added 204

---
 204/main.cpp | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 204/main.cpp

(limited to '204/main.cpp')

diff --git a/204/main.cpp b/204/main.cpp
new file mode 100644
index 0000000..64a11e2
--- /dev/null
+++ b/204/main.cpp
@@ -0,0 +1,52 @@
+#include <iostream>
+
+#include "include/praktable.hpp"
+
+using table = prak::table<f64>;
+using f64p = prak::pvalue<f64>;
+using f64v = std::vector<f64>;
+using vecarg = const std::vector<f64> &;
+using argvec = const std::vector<f64> &;
+
+void ex1(std::string file) {
+	table t(file);
+	f64p F1 = {0.0215, 0.0005}, D = {0.0061, 0.0001}, k = {0.91, 0.01};
+	f64 sgm = (D.err / D.val) * (D.err / D.val) + (k.err / k.val) * (k.err / k.val);
+	f64 F_err = std::sqrt(2.0) * F1.err;
+	t	.apply([&F1](vecarg a){ return a[0] - F1.val;},  {"F2"}, "F")
+		.apply([&](vecarg a){ return a[0] / (2 * k.val * prak::PI * D.val);}, {"F"}, "s")
+		.apply([&](vecarg a){ return a[0] * std::sqrt(F_err * F_err / (a[1] * a[1]) + sgm);}, {"s", "F"}, "ss")
+		.write_plot("s(T).plot", "T", "s", "ss")
+		.add_columns({"q", "sq", "U", "sU"});
+	auto [A, B] = t.least_squares_linear("T", "s", std::make_optional("ss"), std::nullopt);
+	t	.apply([&A](vecarg a){ return -a[0] * A.val;}, {"T"}, "q")
+		.apply([&A](vecarg a){ return a[0] * A.err;}, {"T"}, "sq")
+		.apply_function(prak::sum<f64>, {"s", "q"}, {"ss", "sq"}, "U", "sU")
+		.write_plot("q(T).plot", "T", "q", "sq")
+		.write_plot("U(T).plot", "T", "U", "sU")
+		.print();
+	auto [qA, qB] = t.least_squares_linear("T", "q", "sq", std::nullopt);
+	auto [UA, UB] = t.least_squares_linear("T", "U", "sU", std::nullopt);
+	std::cout 
+		<< "s(T)" << A << "x+" << B << std::endl
+		<< "q(T)" << qA << "x+" << qB << std::endl
+		<< "U(T)" << UA << "x+" << UB << std::endl;
+}
+
+void ex2(std::string file) {
+	table t(file);
+	const char* strs = "1234";
+	std::string x = "x";
+	std::string f = "f";
+	std::string l = "f(x)";
+	for (int i = 0; i < 4; ++i) {
+		table _t({x, f}, {t.begin(x + strs[i]), t.begin(f + strs[i])}, t.find_index(x + strs[i], 0));
+		_t.write_plot(l + strs[i] + ".plot", "x", "f", std::nullopt).print();
+	}
+}
+
+int main() {
+	ex1("data");	
+	ex2("data2");
+	return 0;
+}
-- 
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