From 45f12ba19761024d335407793ffb8d4823b28149 Mon Sep 17 00:00:00 2001
From: justanothercatgirl <sotov2070@gmail.com>
Date: Tue, 15 Apr 2025 00:51:40 +0300
Subject: Started doing 207

---
 207/main.cpp | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 207/main.cpp

(limited to '207/main.cpp')

diff --git a/207/main.cpp b/207/main.cpp
new file mode 100644
index 0000000..6f606bd
--- /dev/null
+++ b/207/main.cpp
@@ -0,0 +1,86 @@
+#include <cmath>
+#include <iostream>
+#include <ranges>
+
+#include "include/praktable.hpp"
+#include "include/prakphys.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> &;
+
+f64p add_nu(table& t) {
+	t.add_column("nu").apply([](vecarg a) { return a[0] * a[1] / (prak::R<f64> * a[2]); }, {"P", "V", "T"}, "nu");
+	return {t.col_avg("nu"), t.col_stddev("nu")};
+}
+
+void ex1(table &t1, const char *name) {
+	f64 DA = prak::discrete_integral_trapezoid(t1.cbegin("V"), t1.cend("V"), t1.cbegin("P"), t1.cend("P"));
+	f64 DS = DA / t1.col_avg("T");
+	f64p nu = add_nu(t1);
+	f64p DS_teor = nu * prak::R<f64> * std::abs(std::log(*(t1.end("V")-1) / *t1.begin("V")));
+	std::cout << "Упражнение 1\n" var(DA) var(DS) var(nu) var(DS_teor) << std::endl;
+	t1.write_plot(std::string("P(V)") + name + ".plot", "V", "P", std::nullopt);
+	t1.write_plot(std::string("PV(V)") + name + ".plot", "V", "x", std::nullopt);
+	std::ofstream f(std::string("ex1_") + name + ".print");
+	f << "Данные упражнения 1";
+	t1.print(f);
+	f.close();
+}
+
+void ex2(const table &t) {
+	
+}
+
+void ex3(const table &t) {
+
+}
+
+void ex4(void) {
+
+}
+
+void ex(void) {
+	table tables[] = {table("data1"), table("data2"), table("data3"), table("data4")};
+
+	// approximate how the volume should have changed in ex3 using parabola
+	std::vector<f64> mrxdata; mrxdata.reserve(9);
+	std::vector<f64> mrydata; mrydata.reserve(3);
+	for (size_t i = 0; i < tables[2].rows; ++i) {
+		if (f64 v; !std::isnan(v = tables[2]["V", i])) {
+			f64 n = tables[2]["n", i];
+			mrxdata.push_back(n*n);
+			mrxdata.push_back(n);
+			mrxdata.push_back(1);
+			mrydata.push_back(v);
+		}
+	}
+	prak::matrix<f64> xs(3, 3, std::move(mrxdata)), ys(3, 1, std::move(mrydata));
+	prak::matrix<f64> poly = xs.inv().value() * ys;
+	for (size_t i = 0; i < tables[2].rows; ++i)
+		tables[2]["V", i] = (poly.tr() * prak::matrix<f64>(3, 1, {(double)(i+1)*(i+1), (double)(i+1), 1}))[0, 0];
+
+	std::function<f64(vecarg)> fs[] = {
+		[](vecarg a) { return a[0] * a[1]; },
+		[](vecarg a) { return a[0] / a[1]; },
+		[](vecarg a) { return a[0] / a[1]; },
+		[](vecarg a) { return a[0] * a[1]; },
+	};
+	std::vector<std::string> vs[] = {
+		{"P", "V"}, {"V", "T"}, {"P", "T"}, {"P", "V"},
+	};
+	for (auto elem : std::views::zip(tables, fs, vs))
+		std::get<0>(elem).apply(std::get<1>(elem), std::get<2>(elem), "x");
+	ex1(tables[0], "1");
+	ex1(tables[3], "4");
+	ex2(tables[1]);
+	ex3(tables[2]);
+	ex4();
+}
+
+int main() {
+	ex();	
+	return 0;
+}
-- 
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