Add linear algebra

backend/api/formula_data/__init__.py

@@ -17,6 +17,8 @@
 from .physics_ii import FORMULAS as PHYSICS_II, CLASS_NAME as PHYSICS_II_NAME
 from .statistics_i import FORMULAS as STATISTICS_I, CLASS_NAME as STATISTICS_I_NAME
 from .statistics_ii import FORMULAS as STATISTICS_II, CLASS_NAME as STATISTICS_II_NAME
+from .linear_algebra_i import FORMULAS as LINEAR_ALGEBRA_I, CLASS_NAME as LINEAR_ALGEBRA_I_NAME
+from .linear_algebra_ii import FORMULAS as LINEAR_ALGEBRA_II, CLASS_NAME as LINEAR_ALGEBRA_II_NAME
 
 AVAILABLE_CLASSES = [
     PRE_ALGEBRA_NAME,
@@ -33,6 +35,8 @@
     PHYSICS_II_NAME,
     STATISTICS_I_NAME,
     STATISTICS_II_NAME,
+    LINEAR_ALGEBRA_I_NAME,
+    LINEAR_ALGEBRA_II_NAME,
 ]
 
 # Classes that have categories (normal structure)
@@ -50,6 +54,8 @@
     PHYSICS_II_NAME,
     STATISTICS_I_NAME,
     STATISTICS_II_NAME,
+    LINEAR_ALGEBRA_I_NAME,
+    LINEAR_ALGEBRA_II_NAME,
 ]
 
 # Special classes with no categories (single toggle)
@@ -71,6 +77,8 @@
     PHYSICS_II_NAME: PHYSICS_II,
     STATISTICS_I_NAME: STATISTICS_I,
     STATISTICS_II_NAME: STATISTICS_II,
+    LINEAR_ALGEBRA_I_NAME: LINEAR_ALGEBRA_I,
+    LINEAR_ALGEBRA_II_NAME: LINEAR_ALGEBRA_II,
 }
 
 

backend/api/formula_data/linear_algebra_i.py

@@ -0,0 +1,20 @@
+""" LINEAR ALGEBRA I formulas """
+CLASS_NAME = "LINEAR ALGEBRA I"
+
+FORMULAS = {
+    "Vector Basics": [
+        {"name": "Vector Addition", "latex": r"\mathbf{u} + \mathbf{v} = \langle u_1+v_1, u_2+v_2 \rangle"},
+        {"name": "Scalar Multiplication", "latex": r"k\mathbf{u} = \langle ku_1, ku_2 \rangle"},
+        {"name": "Magnitude (L2 Norm)", "latex": r"\|\mathbf{v}\| = \sqrt{v_1^2 + v_2^2 + \dots + v_n^2}"},
+        {"name": "Dot Product", "latex": r"\mathbf{u} \cdot \mathbf{v} = u_1v_1 + u_2v_2 + \dots + u_nv_n"},
+    ],
+    "Matrix Operations": [
+        {"name": "Matrix Addition", "latex": r"A + B = [a_{ij} + b_{ij}]"},
+        {"name": "Matrix-Vector Multiplication", "latex": r"A\mathbf{x} = \mathbf{b}"},
+        {"name": "Transpose", "latex": r"(A^T)_{ij} = A_{ji}"},
+    ],
+    "2x2 Systems": [
+        {"name": "2x2 Determinant", "latex": r"\det(A) = ad - bc"},
+        {"name": "2x2 Inverse", "latex": r"A^{-1} = \frac{1}{ad-bc} \begin{bmatrix} d & -b \\ -c & a \end{bmatrix}"},
+    ]
+}

backend/api/formula_data/linear_algebra_ii.py

@@ -0,0 +1,19 @@
+""" LINEAR ALGEBRA II formulas """
+CLASS_NAME = "LINEAR ALGEBRA II"
+
+FORMULAS = {
+    "Matrix Properties": [
+        {"name": "Invertibility Condition", "latex": r"A \text{ is invertible iff } \det(A) \neq 0"},
+        {"name": "Matrix Multiplication Property", "latex": r"(AB)^{-1} = B^{-1}A^{-1}"},
+        {"name": "Orthogonality", "latex": r"Q^T Q = I"},
+    ],
+    "Eigenvalues & Eigenvectors": [
+        {"name": "Characteristic Equation", "latex": r"\det(A - \lambda I) = 0"},
+        {"name": "Eigenvector Definition", "latex": r"A\mathbf{v} = \lambda\mathbf{v}"},
+    ],
+    "Decompositions & Spaces": [
+        {"name": "Diagonalization", "latex": r"A = PDP^{-1}"},
+        {"name": "Rank-Nullity Theorem", "latex": r"\text{rank}(A) + \text{nullity}(A) = n"},
+        {"name": "Projection Formula", "latex": r"\text{proj}_{\mathbf{u}}(\mathbf{v}) = \frac{\mathbf{u} \cdot \mathbf{v}}{\|\mathbf{u}\|^2}\mathbf{u}"},
+    ]
+}

backend/api/latex_utils.py

@@ -30,7 +30,6 @@
     "large": ("1.2pt", "1.2pt"),
 }
 
-
 FONT_SIZE_PATTERN = re.compile(r"^(\d+(?:\.\d+)?)pt$")
 SPACING_PATTERN = re.compile(r"^(\d+(?:\.\d+)?)pt$")
 BODY_FONT_COMMAND_PATTERN = re.compile(
@@ -47,7 +46,7 @@
 LEGACY_ANSWER_LABEL_PATTERN = re.compile(r"\\textbf\{Answer:\}\s*")
 APP_LAYOUT_COMMENT_LINE_PATTERN = re.compile(r"(?m)^% @cheatsheet-layout .*\n?")
 APP_LAYOUT_COMMENT_BLOCK_PATTERN = re.compile(
-    r"(?m)(?:^% @cheatsheet-layout .*\n){4}^%\n?"
+    r"(?m)(?:^% @cheatsheet-layout .*\n)+^%\n?"
 )
 
 
@@ -130,31 +129,42 @@ def append_text_heading(lines, text):
     lines.append(r"\noindent " + text + r"\par")
 
 
-def build_layout_comment_block(columns=4, font_size="9pt", margins="0.15in", spacing="small"):
+def build_layout_comment_block(columns=4, font_size="9pt", margins="0.15in", spacing="small", orientation="portrait"):
     return [
         f"% @cheatsheet-layout columns: {columns} | change layout options up top to update columns",
         f"% @cheatsheet-layout font_size: {font_size} | change layout options up top to update text size",
         f"% @cheatsheet-layout spacing: {spacing} | change layout options up top to update spacing",
         f"% @cheatsheet-layout margins: {margins} | change layout options up top to update margins",
+        f"% @cheatsheet-layout orientation: {orientation} | change layout options up top to update orientation",
         "%",
     ]
 
 
-def build_dynamic_header(columns=4, font_size="9pt", margins="0.15in", spacing="small"):
+def build_dynamic_header(columns=4, font_size="9pt", margins="0.15in", spacing="small", orientation="portrait"):
     """
     Build a dynamic LaTeX header based on user-selected options.
     """
     size_command = get_body_font_command(font_size)
     spacing_values = get_spacing_values(spacing, font_size)
     doc_class, doc_class_size = get_document_class(font_size)
+
+    # 1. Force the PDF driver to rotate by passing landscape and letterpaper to the document class
+    doc_options = f"{doc_class_size},fleqn,letterpaper"
+    if orientation == "landscape":
+        doc_options += ",landscape"
+
+    # 2. Also pass them to the geometry package
+    geometry_options = f"letterpaper,margin={margins}"
+    if orientation == "landscape":
+        geometry_options += ",landscape"
 
     header_lines = [
-        f"\\documentclass[{doc_class_size},fleqn]{{{doc_class}}}",
-        f"\\usepackage[margin={margins}]{{geometry}}",
+        f"\\documentclass[{doc_options}]{{{doc_class}}}",
+        f"\\usepackage[{geometry_options}]{{geometry}}",
         "\\usepackage{amsmath, amssymb}",
         "\\usepackage{enumitem}",
         "\\usepackage{multicol}",
-        "\\usepackage{adjustbox}",  # For auto-scaling equations to fit column width
+        "\\usepackage{adjustbox}",  
         "",
         "\\setlength{\\mathindent}{0pt}",
         "\\setlist[itemize]{noitemsep, topsep=0pt, leftmargin=*}",
@@ -188,12 +198,12 @@ def build_dynamic_footer(columns=2):
     return "\n".join(footer_lines)
 
 
-def normalize_latex_layout(content, columns=4, font_size="9pt", margins="0.15in", spacing="small"):
+def normalize_latex_layout(content, columns=4, font_size="9pt", margins="0.15in", spacing="small", orientation="portrait"):
     """Rebuild document wrappers so current layout controls apply to existing LaTeX content."""
     if not content:
         return content
 
-    header = build_dynamic_header(columns, font_size, margins, spacing)
+    header = build_dynamic_header(columns, font_size, margins, spacing, orientation)
     footer = build_dynamic_footer(columns)
 
     if r"\begin{document}" not in content or r"\end{document}" not in content:
@@ -219,26 +229,26 @@ def normalize_latex_layout(content, columns=4, font_size="9pt", margins="0.15in"
         body = re.sub(r"(?m)^\\vspace\{[^}]+\}\s*$", rf"\\vspace{{{formula_gap}}}", body)
     body = body.strip("\n")
 
-    layout_comment_block = "\n".join(build_layout_comment_block(columns, font_size, margins, spacing))
+    layout_comment_block = "\n".join(build_layout_comment_block(columns, font_size, margins, spacing, orientation))
     body = layout_comment_block + ("\n" + body if body else "")
 
     return header + body + ("\n" if body else "") + footer
 
 
-def build_latex_for_formulas(selected_formulas, columns=4, font_size="9pt", margins="0.15in", spacing="small"):
+def build_latex_for_formulas(selected_formulas, columns=4, font_size="9pt", margins="0.15in", spacing="small", orientation="portrait"):
     """
     Given a list of selected formulas (each with class_name, category, name, latex),
     build a complete LaTeX document.
     """
-    header = build_dynamic_header(columns, font_size, margins, spacing)
+    header = build_dynamic_header(columns, font_size, margins, spacing, orientation)
     footer = build_dynamic_footer(columns)
     formula_gap = get_spacing_values(spacing, font_size)["formula_gap"]
 
     if not selected_formulas:
         return header + footer
 
     body_lines = []
-    body_lines.extend(build_layout_comment_block(columns, font_size, margins, spacing))
+    body_lines.extend(build_layout_comment_block(columns, font_size, margins, spacing, orientation))
     current_class = None
     current_category = None
     in_flushleft = False
@@ -334,4 +344,4 @@ def compile_latex_to_pdf(content):
 
         # Read and return the PDF bytes before the temporary directory is removed
         with open(pdf_file_path, "rb") as pdf_file:
-            return pdf_file.read()
+            return pdf_file.read()

backend/api/migrations/0008_cheatsheet_orientation.py

@@ -0,0 +1,18 @@
+# Generated by Django 6.0.5 on 2026-05-06 02:01
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0007_cheatsheet_content_source'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='cheatsheet',
+            name='orientation',
+            field=models.CharField(default='portrait', max_length=20),
+        ),
+    ]

backend/api/models.py

@@ -39,6 +39,7 @@ class CheatSheet(models.Model):
     margins = models.CharField(max_length=20, default="0.15in")
     font_size = models.CharField(max_length=10, default="9pt")
     spacing = models.CharField(max_length=10, default="small")
+    orientation = models.CharField(max_length=20, default="portrait")
     # Stores selected formulas with user-defined order: [{"class": "...", "category": "...", "name": "..."}]
     selected_formulas = models.JSONField(default=list, blank=True)
     created_at = models.DateTimeField(auto_now_add=True)
@@ -100,12 +101,21 @@ def build_full_latex(self):
         # Build document header
         document_class, document_class_size = get_document_class(self.font_size)
         spacing_values = get_spacing_values(self.spacing, self.font_size)
+
+        doc_options = f"{document_class_size},fleqn,letterpaper"
+        if self.orientation == "landscape":
+            doc_options += ",landscape"
+
+        geometry_options = f"letterpaper,margin={self.margins}"
+        if self.orientation == "landscape":
+            geometry_options += ",landscape"
+
         header = [
-            f"\\documentclass[{document_class_size}]{{{document_class}}}",
+            f"\\documentclass[{doc_options}]{{{document_class}}}",
             "\\usepackage[utf8]{inputenc}",
             "\\usepackage{amsmath, amssymb}",
             "\\usepackage{adjustbox}",
-            f"\\usepackage[a4paper, margin={self.margins}]{{geometry}}",
+            f"\\usepackage[{geometry_options}]{{geometry}}",
             f"\\setlength{{\\baselineskip}}{{{spacing_values['baseline_skip']}}}",
             f"\\setlength{{\\parskip}}{{{spacing_values['paragraph_skip']}}}",
         ]

backend/api/serializers.py

@@ -83,6 +83,7 @@ class Meta:
             "columns",
             "font_size",
             "spacing",
+            "orientation",
             "selected_formulas",
             "problems",
             "full_latex",

backend/api/tests.py

@@ -91,6 +91,7 @@ def test_build_full_latex_wraps_content(self):
             columns=1,
             font_size="10pt",
             user=self.user,
+            orientation="portrait",
         )
         full = sheet.build_full_latex()
         assert "\\begin{document}" in full
@@ -192,7 +193,7 @@ def test_build_full_latex_8pt_uses_extarticle(self):
 
         full = sheet.build_full_latex()
 
-        assert "\\documentclass[8pt]{extarticle}" in full
+        assert "\\documentclass[8pt,fleqn,letterpaper]{extarticle}" in full
 
     def test_build_full_latex_custom_font_size_uses_supported_wrapper(self):
         sheet = CheatSheet.objects.create(
@@ -204,7 +205,7 @@ def test_build_full_latex_custom_font_size_uses_supported_wrapper(self):
 
         full = sheet.build_full_latex()
 
-        assert "\\documentclass[10pt]{article}" in full
+        assert "\\documentclass[10pt,fleqn,letterpaper]{article}" in full
         assert "\\fontsize{10.5pt}{11.3pt}\\selectfont" in full
 
     def test_build_full_latex_includes_saved_spacing(self):
@@ -237,9 +238,9 @@ def test_normalize_latex_layout_rewraps_existing_document_with_current_settings(
             "\\end{document}"
         )
 
-        normalized = normalize_latex_layout(raw, columns=4, font_size="8pt", margins="0.5in", spacing="tiny")
+        normalized = normalize_latex_layout(raw, columns=4, font_size="8pt", margins="0.5in", spacing="tiny", orientation="portrait")
 
-        assert "\\documentclass[8pt,fleqn]{extarticle}" in normalized
+        assert "\\documentclass[8pt,fleqn,letterpaper]{extarticle}" in normalized
         assert "margin=0.5in" in normalized
         assert "\\begin{multicols}{4}" in normalized
         assert "\\begin{multicols}{2}" not in normalized
@@ -383,12 +384,18 @@ def test_build_dynamic_header_keeps_headers_close_to_body_size(self):
 
     def test_build_dynamic_header_accepts_custom_font_and_spacing(self):
         header = build_dynamic_header(columns=5, font_size="10.5pt", margins="0.25in", spacing="0.6pt")
-        assert "\\documentclass[10pt,fleqn]{article}" in header
+        assert "\\documentclass[10pt,fleqn,letterpaper]{article}" in header
         assert "\\fontsize{10.5pt}{11.3pt}\\selectfont" in header
         assert "\\setlength{\\baselineskip}{11.1pt}" in header
         assert "\\setlength{\\parskip}{0.6pt}" in header
         assert "\\begin{multicols}{5}" in header
 
+    def test_build_dynamic_header_landscape_includes_landscape_options(self):
+        header = build_dynamic_header(columns=4, font_size="9pt", margins="0.15in", spacing="small", orientation="landscape")
+        assert "landscape" in header
+        assert "\\documentclass[9pt,fleqn,letterpaper,landscape]{extarticle}" in header
+        assert "letterpaper,margin=0.15in,landscape" in header
+
     def test_build_latex_for_formulas_includes_editable_layout_comments(self):
         tex = build_latex_for_formulas(
             [{"class_name": "ALGEBRA I", "category": "Linear Equations", "name": "Slope Formula", "latex": "m=\\frac{y_2-y_1}{x_2-x_1}"}],
@@ -402,6 +409,7 @@ def test_build_latex_for_formulas_includes_editable_layout_comments(self):
         assert "% @cheatsheet-layout font_size: 10.5pt | change layout options up top to update text size" in tex
         assert "% @cheatsheet-layout spacing: 0.6pt | change layout options up top to update spacing" in tex
         assert "% @cheatsheet-layout margins: 0.5in | change layout options up top to update margins" in tex
+        assert "% @cheatsheet-layout orientation: portrait | change layout options up top to update orientation" in tex
 
 
 # ── API Tests ────────────────────────────────────────────────────────
@@ -1246,7 +1254,7 @@ def test_generate_sheet_8pt_uses_extarticle(self, auth_client):
         )
         assert resp.status_code == 200
         tex = resp.json()["tex_code"]
-        assert "\\documentclass[8pt,fleqn]{extarticle}" in tex
+        assert "\\documentclass[8pt,fleqn,letterpaper]{extarticle}" in tex
         assert "\\documentclass[8pt,fleqn]{article}" not in tex
 
     def test_generate_sheet_9pt_uses_extarticle(self, auth_client):
@@ -1261,7 +1269,7 @@ def test_generate_sheet_9pt_uses_extarticle(self, auth_client):
         )
         assert resp.status_code == 200
         tex = resp.json()["tex_code"]
-        assert "\\documentclass[9pt,fleqn]{extarticle}" in tex
+        assert "\\documentclass[9pt,fleqn,letterpaper]{extarticle}" in tex
         assert "\\documentclass[9pt,fleqn]{article}" not in tex
 
     def test_generate_sheet_10pt_uses_article(self, auth_client):
@@ -1276,7 +1284,7 @@ def test_generate_sheet_10pt_uses_article(self, auth_client):
         )
         assert resp.status_code == 200
         tex = resp.json()["tex_code"]
-        assert "\\documentclass[10pt,fleqn]{article}" in tex
+        assert "\\documentclass[10pt,fleqn,letterpaper]{article}" in tex
         assert "extarticle" not in tex
 
     def test_generate_sheet_latex_injection_blocked(self, auth_client):
@@ -1375,6 +1383,7 @@ def test_compile_normalize_only_refreshes_layout_comments_from_request_values(se
                 "font_size": "8pt",
                 "spacing": "tiny",
                 "margins": "0.25in",
+                "orientation": "portrait",
             },
             format="json",
         )
@@ -1387,6 +1396,7 @@ def test_compile_normalize_only_refreshes_layout_comments_from_request_values(se
             "font_size": "8pt",
             "spacing": "tiny",
             "margins": "0.25in",
+            "orientation": "portrait", 
         }
         assert "\\begin{multicols}{2}" in tex
         assert "\\fontsize{8pt}{8.8pt}\\selectfont" in tex
@@ -1395,6 +1405,7 @@ def test_compile_normalize_only_refreshes_layout_comments_from_request_values(se
         assert "% @cheatsheet-layout font_size: 8pt | change layout options up top to update text size" in tex
         assert "% @cheatsheet-layout spacing: tiny | change layout options up top to update spacing" in tex
         assert "% @cheatsheet-layout margins: 0.25in | change layout options up top to update margins" in tex
+        assert "orientation: portrait" in tex 
 
 
 # ── Auth Endpoint Tests ──────────────────────────────────────────────