added 218, 226, 234, 240

34 files changed, 397 insertions, 8 deletions

diff --git a/218/Makefile b/218/Makefile
new file mode 100644
index 0000000..224506f
--- /dev/null
+++ b/218/Makefile
@@ -0,0 +1,18 @@
+
+CFLAGS = -std=c++2c -mavx -Iinclude -ggdb
+
+.PHONY: all run_main clean gnuplot 
+
+run: gnuplot
+
+gnuplot: plots.gp run_main
+	gnuplot $< &>/dev/null
+
+run_main: main
+	./main
+
+main: main.cpp include/*
+	$(CXX) -o $@ $< $(CFLAGS)
+
+clean: 
+	rm -fr main *.png *.plot
diff --git a/218/README.md b/218/README.md
new file mode 100644
index 0000000..96fd716
--- /dev/null
+++ b/218/README.md
@@ -0,0 +1,5 @@
+<!-- Шаблон для прака -->
+<!-- файлы, заканчивающиеся на .plot считаются генерируемыми и удаляются через make clean -->
+# Обработка <> прака
+
+
diff --git a/218/compile_flags.txt b/218/compile_flags.txt
new file mode 100644
index 0000000..34ae930
--- /dev/null
+++ b/218/compile_flags.txt
@@ -0,0 +1,4 @@
+-Iinclude
+-std=c++2c
+-mavx2
+
diff --git a/218/data b/218/data
new file mode 100644
index 0000000..fe6e835
--- /dev/null
+++ b/218/data
@@ -0,0 +1,8 @@
+dp	dt
+215	7.9
+178	9.5
+150	10.2
+133	11.2
+96	13
+75	15
+56	18
diff --git a/218/include b/218/include
new file mode 120000
index 0000000..2225752
--- /dev/null
+++ b/218/include
@@ -0,0 +1 @@
+../libprakpp/include/
\ No newline at end of file
diff --git a/218/main.cpp b/218/main.cpp
new file mode 100644
index 0000000..379804a
--- /dev/null
+++ b/218/main.cpp
@@ -0,0 +1,19 @@
+#include <iostream>
+#include "include/praktable.hpp"
+#include "include/prakphys.hpp"
+
+int main() {
+	prak::table<f64> t("data");
+	t	.add_column("1/dt")
+		.apply(prak::inv<f64>, "dt", "1/dt")
+		.write_plot("1dt(dp).plot", "dp", "1/dt", std::nullopt)
+		.print();
+	auto [A, B] = t.least_squares_linear("dp", "1/dt", std::nullopt, 0.00001);
+	f64 W = 3.82;
+	prak::pvalue<f64> beta = {1.51e-6, 0.05e-6}, T0 = {298.5, 1}, p0 = {0.99e5, 500},
+		CPR = A * W * T0 / beta / p0, CP = CPR * prak::R<f64>,
+		CVR = CPR - 1.0, CV = CVR * prak::R<f64>, i = 2.0*CV/prak::R<f64>;
+	
+	std::cout var(A) var(B) var(beta) var(p0) var(CPR) var(CP) var(CVR) var(CV) var(i) << std::endl;
+	return 0;
+}
diff --git a/218/plots.gp b/218/plots.gp
new file mode 100644
index 0000000..eb9516c
--- /dev/null
+++ b/218/plots.gp
@@ -0,0 +1,16 @@
+set term pngcairo size 1000, 800
+set grid
+
+f1(x) = a1*x+b1
+fit f1(x) '1dt(dp).plot' via a1, b1
+
+set output '1dt(dp).png'
+set title "График зависимости велечины, обратной температуре воздуха, от разницы давлений"
+set xlabel "1/T (1/К)"
+set ylabel "P (Па)"
+set key top left
+
+set label sprintf("A = %.4g\n B = %.4g", a1, b1) at graph 0.2, 0.9 front boxed
+plot 	'1dt(dp).plot' notitle lc 0 pt 1 lw 2,	\
+	f1(x) title "1/dT(dP)" lc rgb "red"
+
diff --git a/219/main.cpp b/219/main.cpp
index f6fc4e2..d5a4735 100644
--- a/219/main.cpp
+++ b/219/main.cpp
@@ -25,14 +25,14 @@ f64p (ex1) (std::string file) {
 	     L = {0.25, 0.005},
 	     r_2 = {0.006, 5e-6}, r_1 = {0.075e-3, 5e-6},
 	     k = prak::function<f64>([](vecarg a){ return a[0] * a[1] / (2 * prak::PI * a[2] * a[3]) * std::log(a[4]/a[5]);}, {alpha, B, L, A, r_2, r_1});
-	std::cout << "k = " << k << '\n';
+	std::cout var(alpha) var (L) var(r_1) var(r_2) << "k = " << k << '\n';
 	f64p eps = {0.35, 0.005}, sgm = {5.67e-8, 0.01e-8}, 
 	     S = prak::function<f64>([](vecarg a){ return 2 * prak::PI * a[0] * a[1]; }, {r_1, L}),
 	     R = {t.col_avg("R"), 0}, dT = prak::function<f64>([](vecarg a){return std::abs((a[0] - a[1])/(a[1]*a[2]));}, {R, B, alpha}),
 	     T_0 = {295, 5}, T_1 = T_0 + dT, W_rad = eps * sgm * (T_1*T_1*T_1*T_1 - T_0*T_0*T_0*T_0)*S, 
 	     g = {9.8, 0.05}, beta = 1.0 / T_0, nu = {1.6e-5, 0.1e-5}, Gr = g * beta * L * L * L * dT / nu / nu,
 	     alpha2 = 0.75 * k / L * ((0.7 * Gr) ^ 0.25), W_con = alpha2 * dT * S;
-	std::cout var(eps) var(sgm) var(R) var(dT) var(T_0) var(T_1) var(W_rad) var(beta) var(nu) var(Gr) var(alpha2) var(W_con);
+	std::cout var(eps) var(sgm) var(R) var(dT) var(T_0) var(T_1) var(S) var(W_rad) var(beta) var(nu) var(Gr) var(alpha2) var(W_con);
 	return k;
 }
 
@@ -54,8 +54,8 @@ f64p (ex2) (const std::string& s) {
 
 int (main) (void) {
 	std::cout << ex1("data") / ex2("data2") / 2.0  
-		  << " = C_P\nпо табличным значениям: C_P = " << 0.0259 / 0.001004 / 2
-		  << "\nПо здравому смыслу:7/2R = " << 7.0/2 * 8.31  << std::endl;
+		  << " = C_V\nпо табличным значениям: C_V = " << 0.0259 / 0.001004 / 2
+		  << "\nПо здравому смыслу:5/2R = " << 5.0/2 * 8.31  << std::endl;
 
 	return 0;
 }
diff --git a/226/Makefile b/226/Makefile
new file mode 100644
index 0000000..224506f
--- /dev/null
+++ b/226/Makefile
@@ -0,0 +1,18 @@
+
+CFLAGS = -std=c++2c -mavx -Iinclude -ggdb
+
+.PHONY: all run_main clean gnuplot 
+
+run: gnuplot
+
+gnuplot: plots.gp run_main
+	gnuplot $< &>/dev/null
+
+run_main: main
+	./main
+
+main: main.cpp include/*
+	$(CXX) -o $@ $< $(CFLAGS)
+
+clean: 
+	rm -fr main *.png *.plot
diff --git a/226/README.md b/226/README.md
new file mode 100644
index 0000000..96fd716
--- /dev/null
+++ b/226/README.md
@@ -0,0 +1,5 @@
+<!-- Шаблон для прака -->
+<!-- файлы, заканчивающиеся на .plot считаются генерируемыми и удаляются через make clean -->
+# Обработка <> прака
+
+
diff --git a/226/compile_flags.txt b/226/compile_flags.txt
new file mode 100644
index 0000000..34ae930
--- /dev/null
+++ b/226/compile_flags.txt
@@ -0,0 +1,4 @@
+-Iinclude
+-std=c++2c
+-mavx2
+
diff --git a/226/data b/226/data
new file mode 100644
index 0000000..629cedb
--- /dev/null
+++ b/226/data
@@ -0,0 +1,8 @@
+U	T1	T2	T3	sT1	sT2	sT3	T	sT	dU	sdU	vpr	epr
+2.1	575	539	610	63	99	74	?	?	1	0.01	139	0.02
+2.26	647	651	671	78	64	71	?	?	1	0.01	143	0.04
+2.4	882	886	872	76	84	99	?	?	1.02	0.01	171	?
+2.54	1021	1079	1033	151	137	126	?	?	1.03	0.02	193	?
+2.68	1089	1143	1121	157	87	88	?	?	1.026	0.01	196	?
+2.82	1111	1160	1053	183	237	287	?	?	0.997	0.03	206	?
+3.0	1109	1063	1089	251	242	265	?	?	0.957	0.03	206	?
diff --git a/226/include b/226/include
new file mode 120000
index 0000000..2225752
--- /dev/null
+++ b/226/include
@@ -0,0 +1 @@
+../libprakpp/include/
\ No newline at end of file
diff --git a/226/main.cpp b/226/main.cpp
new file mode 100644
index 0000000..9584e60
--- /dev/null
+++ b/226/main.cpp
@@ -0,0 +1,32 @@
+#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> &;
+
+void ex1(std::string file) {
+	table t(file);
+	t	.apply(prak::avg<f64>, {"T1", "T2", "T3"}, "T")
+		.apply([](vecarg a){
+			return std::sqrt(std::pow(prak::stddev<f64>({a[0], a[1], a[2]}), 2) 
+				+ std::pow(prak::avg<f64>({a[3], a[4], a[5]}), 2)/3.0);
+		}, {"T1", "T2", "T3", "sT1", "sT2", "sT3"}, "sT")
+		.add_columns({"Tv", "sTv", "Te", "sTe"})
+		.add_columns({"svpr", "sepr"}, 6e3)
+		.multiply_column("vpr", 1e3)
+		.multiply_column("epr", conv::eV_to_J<f64>)
+		.apply_function([](vecarg a){return prak::m_e<f64> * a[0] * a[0] / (2 * prak::k<f64>);}, {"vpr"}, {"svpr"}, "Tv", "sTv")
+		.apply_function([](vecarg a){return 2 * a[0] / prak::k<f64>;}, {"epr"}, {"sepr"}, "Te", "sTe")
+		.delete_cols({"svpr", "sepr", "sTe"})
+		.write_plot("T(U).plot", "U", "T", "sT")
+		.write_plot("Tv(U).plot", "U", "Tv", "sTv")
+		.print();
+}
+
+int main() {
+	ex1("data");
+	return 0;
+}
diff --git a/226/plot.pdf b/226/plot.pdf
new file mode 100644
index 0000000..339cdf8
--- /dev/null
+++ b/226/plot.pdf
diff --git a/226/plots.gp b/226/plots.gp
new file mode 100644
index 0000000..853d03d
--- /dev/null
+++ b/226/plots.gp
@@ -0,0 +1,24 @@
+set term pngcairo size 2400, 2000 font "Arial,30"
+set grid lw 4
+
+f1(x) = a1*x + b1
+f2(x) = a2*x + b2
+
+fit f1(x) 'T(U).plot' using 1:2:3 yerr via a1,b1
+a2=a1
+fit f2(x) 'Tv(U).plot' using 1:2:3 yerr via a2,b2
+
+set output 'plot.png'
+set title "Зависимость температур термоэлектронов от напряжения накала"
+set xlabel "U, В"
+set ylabel "T, К"
+set key top left
+
+set xrange[2.09:3.01]
+
+plot 	'T(U).plot' using 1:2:3 with yerrorbars title "Расчёт по программе" lc rgb("blue") pt 2 lw 5,	\
+	f1(x) lc rgb "red" lw 3 title "Расчёт по программе",			\
+	'Tv(U).plot' using 1:2:3 with yerrorbars title "расчёт по v_{нв}" lc rgb("orange") pt 3 lw 5,	\
+	f2(x) lc rgb "green" lw 3 title "расчёт по v_{нв}"
+#'T(U).plot' with lines smooth csplines lc rgb "red" lw 3 title "Расчёт по ",			\
+#'Tv(U).plot' with lines smooth csplines lc rgb "green" lw 3 title "Расчёт по v_{нв}"
diff --git a/234/Makefile b/234/Makefile
new file mode 100644
index 0000000..224506f
--- /dev/null
+++ b/234/Makefile
@@ -0,0 +1,18 @@
+
+CFLAGS = -std=c++2c -mavx -Iinclude -ggdb
+
+.PHONY: all run_main clean gnuplot 
+
+run: gnuplot
+
+gnuplot: plots.gp run_main
+	gnuplot $< &>/dev/null
+
+run_main: main
+	./main
+
+main: main.cpp include/*
+	$(CXX) -o $@ $< $(CFLAGS)
+
+clean: 
+	rm -fr main *.png *.plot
diff --git a/234/README.md b/234/README.md
new file mode 100644
index 0000000..96fd716
--- /dev/null
+++ b/234/README.md
@@ -0,0 +1,5 @@
+<!-- Шаблон для прака -->
+<!-- файлы, заканчивающиеся на .plot считаются генерируемыми и удаляются через make clean -->
+# Обработка <> прака
+
+
diff --git a/234/compile_flags.txt b/234/compile_flags.txt
new file mode 100644
index 0000000..34ae930
--- /dev/null
+++ b/234/compile_flags.txt
@@ -0,0 +1,4 @@
+-Iinclude
+-std=c++2c
+-mavx2
+
diff --git a/234/data3 b/234/data3
new file mode 100644
index 0000000..3b9cb69
--- /dev/null
+++ b/234/data3
@@ -0,0 +1,7 @@
+n	s	s2	sn	t
+0.3881	0.6102	?	?	2
+1.97	1.411	?	?	10
+3.834	1.885	?	?	20
+7.802	2.738	?	?	40
+16.08	3.8	?	?	80
+31.71	5.75	?	?	160
diff --git a/234/include b/234/include
new file mode 120000
index 0000000..2225752
--- /dev/null
+++ b/234/include
@@ -0,0 +1 @@
+../libprakpp/include/
\ No newline at end of file
diff --git a/234/main.cpp b/234/main.cpp
new file mode 100644
index 0000000..6762d1c
--- /dev/null
+++ b/234/main.cpp
@@ -0,0 +1,76 @@
+#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> &;
+
+f64 factorial(u64 times) {
+	f64 res = 1;
+	for (; times; res *= times--);
+	return res;
+}
+
+f64 poisson(u64 at, f64 avg) {
+	return std::pow(avg, at) * std::exp(-avg) / factorial(at);
+}
+
+template <typename lambda, typename...Args>
+f64 distr_sum(lambda f, u64 from, u64 to, Args...args) {
+	f64 res = 0;
+	for(; from <= to; res += f(from++, args...));
+	return res;
+}
+
+void ex1() {
+	f64 n = 1.053, s = 0.582553;
+	std::cout << "ex 1:\n"
+		var(distr_sum(poisson, n, n, n)) 
+		var(distr_sum(poisson, n, n+1, n))
+		var(distr_sum(poisson, std::round(n-s), std::round(n+s), n))
+		var(distr_sum(poisson, std::round(n-2*s), std::round(n+2*s), n))
+	<< std::endl;
+}
+table ex3(const char* file) {
+	table t(file);
+	t	.apply([](argvec a){return a[0]*a[0];}, "s", "s2")
+		.apply([](argvec a){return a[0]/a[1];}, std::vector<std::string>{"s", "n"}, "sn")
+		.write_plot("s(n).plot" , "n", "s", std::nullopt)
+		.write_plot("s2(n).plot", "n", "s2", std::nullopt)
+		.write_plot("sn(n).plot", "n", "sn", std::nullopt)
+		.print();
+	return t;
+}
+void ex4(table t0) {
+	table t1({"count", "N", "n1", "s1", "n2", "s2", "s", "s/sn1", "s/sn2", "sqrtn1", "sqrtn2"}, 6, 0);
+	f64 T1 = 45e-3;
+	f64 T2 = 0.625;
+	for (int i = 0; i < 6; ++i) {
+		t1["count", i] = i+1;
+		t1["N", i] = t0["n", i] / t0["t", i] * 1000;
+		t1["s", i] = t0["s", i] / std::sqrt(t0["t", i] / 1000);
+	}
+	t1	.apply([T1](vecarg a){return a[0]*T1;}, "N", "n1")
+		.apply([T1](vecarg a){return a[0]*std::sqrt(T1);}, "s", "s1")
+		.apply([T2](vecarg a){return a[0]*T2;}, "N", "n2")
+		.apply([T2](vecarg a){return a[0]*std::sqrt(T2);}, "s", "s2");
+	f64	avgn1 = t1.col_avg("n1"),
+		avgn2 = t1.col_avg("n2"),
+		savgn1 = t1.col_stddev("n1"),
+		savgn2 = t1.col_stddev("n2");
+	t1	.apply([savgn1](vecarg a){return a[0]/savgn1;}, "s1", "s/sn1")
+		.apply([savgn2](vecarg a){return a[0]/savgn2;}, "s2", "s/sn2")
+		.apply([](vecarg a){return std::sqrt(a[0]);}, "n1", "sqrtn1")
+		.apply([](vecarg a){return std::sqrt(a[0]);}, "n2", "sqrtn2")
+		.print();
+	std::cout var(avgn1)var(avgn2)var(savgn1)var(savgn2);
+}
+
+int main() {
+	ex1();
+	ex4(ex3("data3"));
+	return 0;
+}
diff --git a/234/plots.gp b/234/plots.gp
new file mode 100644
index 0000000..a357dca
--- /dev/null
+++ b/234/plots.gp
@@ -0,0 +1,30 @@
+set term pngcairo size 1000, 800
+set grid
+
+f1(x) = a1*sqrt(b1*x)
+f2(x) = a2/(x-b2)+c2
+f3(x) = a3*x+b3
+fit f1(x) 's(n).plot' using 1:2 via a1, b1
+fit f2(x) 'sn(n).plot' using 1:2 via a2, b2, c2
+fit f3(x) 's2(n).plot' using 1:2 via a3, b3
+
+set output 's(n).png'
+set title "График зависимости дисперсии, стандартного отклонения и относительной флуктуации от среднего"
+set y2tics
+set xlabel "n, среднее"
+set ylabel "s, s/n"
+set y2label "s^2"
+set key top lef
+set yrange[0:7]
+set y2range[0:35]
+
+
+plot 	's(n).plot' with lines title "s(n)" lc rgb('red')  lw 2,	\
+	'sn(n).plot' with lines title "s/n(n)" lc rgb('blue') lw 2,	\
+	's2(n).plot' with lines title "s^2(n)" axes x1y2 lc rgb('green') lw 2,	\
+	's(n).plot' lc 0 pt 2 lw 2 notitle,\
+	'sn(n).plot' lc 0 pt 2 lw 2 notitle,\
+	's2(n).plot' lc 0 pt 2 lw 2 axes x1y2 notitle,\
+	f1(x) lc 0 lw 1 dashtype(20,10) notitle,\
+	f2(x) lc 0 lw 1 dashtype(20,10) notitle,\
+	f3(x) axes x1y2 notitle lc 0 lw 1 dashtype(20,10)
diff --git a/240/Makefile b/240/Makefile
new file mode 100644
index 0000000..224506f
--- /dev/null
+++ b/240/Makefile
@@ -0,0 +1,18 @@
+
+CFLAGS = -std=c++2c -mavx -Iinclude -ggdb
+
+.PHONY: all run_main clean gnuplot 
+
+run: gnuplot
+
+gnuplot: plots.gp run_main
+	gnuplot $< &>/dev/null
+
+run_main: main
+	./main
+
+main: main.cpp include/*
+	$(CXX) -o $@ $< $(CFLAGS)
+
+clean: 
+	rm -fr main *.png *.plot
diff --git a/240/README.md b/240/README.md
new file mode 100644
index 0000000..96fd716
--- /dev/null
+++ b/240/README.md
@@ -0,0 +1,5 @@
+<!-- Шаблон для прака -->
+<!-- файлы, заканчивающиеся на .plot считаются генерируемыми и удаляются через make clean -->
+# Обработка <> прака
+
+
diff --git a/240/compile_flags.txt b/240/compile_flags.txt
new file mode 100644
index 0000000..34ae930
--- /dev/null
+++ b/240/compile_flags.txt
@@ -0,0 +1,4 @@
+-Iinclude
+-std=c++2c
+-mavx2
+
diff --git a/240/data b/240/data
new file mode 100644
index 0000000..3e38f45
--- /dev/null
+++ b/240/data
@@ -0,0 +1,11 @@
+t	dp1	dp	ln
+4.14	9.31	1.88	?
+5	5.88	1.04	?
+6	6.66	1.19	?
+7.27	1.88	0.25	?
+8.07	6.07	0.88	?
+10	6.61	0.82	?
+15	7.10	0.56	?
+20	6.42	0.32	?
+31	7.59	0.13	?
+
diff --git a/240/include b/240/include
new file mode 120000
index 0000000..2225752
--- /dev/null
+++ b/240/include
@@ -0,0 +1 @@
+../libprakpp/include/
\ No newline at end of file
diff --git a/240/main.cpp b/240/main.cpp
new file mode 100644
index 0000000..52af396
--- /dev/null
+++ b/240/main.cpp
@@ -0,0 +1,28 @@
+#include <iostream>
+
+#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> &;
+
+void ex1(std::string file) {
+	table t(file);
+	t.apply([](argvec a){ return std::log(a[0]/a[1]); }, std::vector<std::string>{"dp1", "dp"}, "ln");
+	t.write_plot("mnk.plot", "t", "ln", std::nullopt);
+	auto [A, B] = t.least_squares_linear("t", "ln", std::nullopt, std::make_optional(0.1));
+	f64p gamma = prak::function<f64>([](vecarg a) { return std::exp(a[0]) / (std::exp(a[0]) - 1); }, {B});
+	f64p Cv = prak::R<f64> / (gamma - 1.0);
+	f64p i = 2.0 * Cv / prak::R<f64>, Cp = Cv + prak::R<f64>;
+	f64 m0 = 1.29 * 0.0127;
+	f64p alpha = m0 * Cp * A, tau = 1.0 / A;
+	std::cout << t var(A) var(B) var(gamma) var(Cv) var(i) var(m0) var(Cp) var(alpha) var(tau);
+}
+
+int main() {
+	ex1("data");	
+	return 0;
+}
diff --git a/240/plots.gp b/240/plots.gp
new file mode 100644
index 0000000..8c71dc0
--- /dev/null
+++ b/240/plots.gp
@@ -0,0 +1,16 @@
+set term pngcairo size 1000, 800
+set grid
+
+f1(x) = a1*x+b1
+fit f1(x) 'mnk.plot' using 1:2 via a1, b1
+
+set output 'mnk.png'
+set title "зависимтость      от t"
+set xlabel "t, c"
+set ylabel "ln dp1/dp(t), ед."
+set key top left
+
+set label sprintf("A = %.4g\n B = %.4g", a1, b1) at graph 0.2, 0.9 front boxed
+plot 	'mnk.plot' using 1:2 notitle lc 0 pt 1 lw 2,	\
+	f1(x) title "y(x)" lc rgb "red"
+
diff --git a/libprakpp/include/prakphys.hpp b/libprakpp/include/prakphys.hpp
index 1eaef5a..1db7a94 100644
--- a/libprakpp/include/prakphys.hpp
+++ b/libprakpp/include/prakphys.hpp
@@ -19,7 +19,7 @@ TP hh = 1.054571817e-34;
 TP k = 1.380649e-23;
 TP G = 6.67430151515e-11;
 TP e = 1.602176634e-19;
-TP m_e = 1.6021766342828e-31;
+TP m_e = 9.109383713928e-31;
 TP m_p = 1.672621925955252e-27;
 TP m_n = 1.674927500568585e-27;
 TP R = 8.31446261815324;
diff --git a/libprakpp/include/praktable.hpp b/libprakpp/include/praktable.hpp
index 2cfa500..f00e7b9 100644
--- a/libprakpp/include/praktable.hpp
+++ b/libprakpp/include/praktable.hpp
@@ -472,7 +472,7 @@ public:
 
 	// Fills a specified column with the same value `v`
 	table &fill_column(const std::string &column, dtype v) {
-		apply([&v](const std::vector<dtype>& _) -> dtype { return v; }, {}, column);
+		apply([&v](const std::vector<dtype>& _) -> dtype { return v; }, std::vector<std::string>{}, column);
 		return *this;
 	}
 
@@ -538,7 +538,7 @@ public:
 		dtype avg = col_avg(column);
 		for (auto it = begin(column); it != end(column); ++it)
 			accum += (*it - avg)*(*it - avg);
-		return std::sqrt(accum);
+		return std::sqrt(accum / rows);
 	}
 
 	// takes columns [columns], calculates average and standard deviation for each row, puts them into `avg` and `stddev` and deleted original columns
diff --git a/tempalte/main.cpp b/tempalte/main.cpp
index 2786234..9980fb8 100644
--- a/tempalte/main.cpp
+++ b/tempalte/main.cpp
@@ -1,6 +1,7 @@
 #include <iostream>
 
 #include "include/praktable.hpp"
+#include "include/prakphys.hpp"
 
 using table = prak::table<f64>;
 using f64p = prak::pvalue<f64>;
diff --git a/tempalte/plots.gp b/tempalte/plots.gp
index 9c2994f..f197258 100644
--- a/tempalte/plots.gp
+++ b/tempalte/plots.gp
@@ -8,8 +8,9 @@ set output ''
 set title ""
 set xlabel ""
 set ylabel ""
+set key top left
 
-#set label sprintf("A = %.4g\n B = %.4g", a1, b1) at graph 0.1, 0.9 front boxed
+#set label sprintf("A = %.4g\n B = %.4g", a1, b1) at graph 0.2, 0.9 front boxed
 #plot 	'.plot' using 1:2:3 with yerrorbars notitle lc 0 pt 1 lw 2,	\
 #	f1(x) title "" lc rgb "red"