regen ker coeffs .h without nc200() etc func; use .size() instead, mu…

…ch neater

devel/gen_all_horner_cpp_header.m

@@ -6,6 +6,7 @@
 % version including low upsampfac, 6/17/18.
 % Ludvig put in w=4n padding, 1/31/20. Mystery about why d was bigger 2/6/20.
 % C++ header using constexpr of Barbone, replacing *_C_code.m. Barnett 7/16/24.
+% simplified to kill nc200() etc functions, Barbone + Barnett 7/22/24.
 clear
 %opts = struct();  % not needed yet
 
@@ -20,34 +21,23 @@
     fid = fopen('../src/ker_lowupsampfac_horner_allw_loop_constexpr.h','w');
   end
   fwrite(fid,sprintf('// Header of static arrays of monomial coeffs of spreading kernel function in each\n'));
-  fwrite(fid,sprintf('// fine-grid interval. Generated by gen_all_horner_cpp_header.m in finufft/devel\n'));
+  fwrite(fid,sprintf('// fine-grid interval. Generated by gen_all_horner_cpp_header.m in devel/\n'));
   fwrite(fid,sprintf('// Authors: Alex Barnett, Ludvig af Klinteberg, Marco Barbone & Libin Lu.\n// (C) 2018--2024 The Simons Foundation, Inc.\n'));
   fwrite(fid,sprintf('#include <array>\n\n'));
 
-  usf_tag = sprintf('%d',100*upsampfac);  % follow Barbone convention: 200 or 125
-  fwrite(fid,sprintf('template<uint8_t w> constexpr auto nc%s() noexcept {\n',usf_tag));
-  fwrite(fid,'  constexpr uint8_t ncs[] = {');    % array of ncoeffs for ws
-  for w=ws
-    [d,~] = get_degree_and_beta(w, upsampfac);
-    nc = d+1;
-    fwrite(fid,sprintf('%d, ',nc));
-  end
-  fwrite(fid,sprintf('};\n  return ncs[w-%d];\n}\n\n',ws(1)));   % finish func code
-  % (must be a func since also called from spreadinterp.cpp)
-
-  fwrite(fid,sprintf('template<class T, uint8_t w>\nconstexpr std::array<std::array<T, w>, nc%s<w>()> get_horner_coeffs_%s() noexcept {\n',usf_tag,usf_tag));
-  fwrite(fid,sprintf('    constexpr auto nc = nc%s<w>();\n',usf_tag));  % use func
+  usf_tag = sprintf('%d',100*upsampfac);  % string, follow Barbone convention: 200 or 125
+  fwrite(fid,sprintf('template<class T, uint8_t w>\nconstexpr auto get_horner_coeffs_%s() noexcept {\n',usf_tag));
 
   for j=1:numel(ws)
     w = ws(j);
     [d,beta] = get_degree_and_beta(w,upsampfac);
     fprintf('w=%d\td=%d\tbeta=%.3g\n',w,d,beta);
-    str = gen_ker_horner_loop_cpp_code(w,d,beta);  % code strings for this w
+    str = gen_ker_horner_loop_cpp_code(w,d,beta);  % code strings for this w (nc hardcoded)
 
     if j==1                                % write switch statement
-      fwrite(fid,sprintf('    if constexpr (w==%d) {\n',w));
+      fwrite(fid,sprintf('    if constexpr (w == %d) {\n',w));
     else
-      fwrite(fid,sprintf('    } else if constexpr (w==%d) {\n',w));
+      fwrite(fid,sprintf('    } else if constexpr (w == %d) {\n',w));
     end
     for i=1:numel(str); fwrite(fid,['    ',str{i}]); end   % format 4 extra spaces
   end

devel/gen_ker_horner_loop_cpp_code.m

@@ -34,22 +34,24 @@
 
 % Ludvig af Klinteberg 4/25/18, based on Barnett 4/23/18. Ludvig wpad 1/31/20.
 % Barnett redo for Barbone templated arrays, no wpad, 7/16/24.
+% hardcoded outer nc array size, 7/22/24.
 
 if nargin==0, test_gen_ker_horner_loop_cpp_code; return; end
 if nargin<4, o=[]; end
 
 C = ker_ppval_coeff_mat(w,d,be,o);
 if d==0, d = size(C,2)-1; end
-str = cell(d+3,1);     % nc = d+1, plus one start and one close-paren line
+nc = d+1;
+str = cell(nc+2,1);     % one coeff per line + one return and one close-paren line
 % code to open the templated array...   why two {{?  (some C++ ambiguity thing)
-str{1} = sprintf('  return std::array<std::array<T, w>, nc> {{\n');
+str{1} = sprintf('  return std::array<std::array<T, w>, %d> {{\n', nc);
 for n=1:d+1                  % loop over poly coeff powers 0,1,..,d
   % sprintf implicitly loops over fine-grid interpolation intervals 1:w...
   coeffrow = sprintf('%.16E, ', C(n,:));
-  coeffrow = coeffrow(1:end-2);   % kill trailing comma even though allowed in C++
-  str{d+3-n} = sprintf('      {%s},\n', coeffrow);    % leaves outer trailing comma
+  coeffrow = coeffrow(1:end-2);   % easy kill trailing comma (but allowed in C++)
+  str{d+3-n} = sprintf('      {%s},\n', coeffrow);   % leave outer trailing comma
 end
-str{d+3} = sprintf('  }};\n');     % terminate the array   why two }}?
+str{nc+2} = sprintf('  }};\n');     % terminate the array (two braces)
 
 
 %%%%%%%%